Business Statistics Test 4
0.0166
A frequency distribution has a mean of 100 and a standard deviation of 20. The class limits for one class are 50 up to 60. Based on the normal distribution, what is the probability that an observation would be in this class?
-2.5 and -2.0
A frequency distribution has a mean of 100 and a standard deviation of 20. The class limits for one class are 50 up to 60. What are the standard normal z-statistics for the class limits?
0.1359
A frequency distribution has a mean of 200 and a standard deviation of 20. The class limits for one class are 220 up to 240. Based on the normal distribution, what is the probability that an observation would be in this class?
Reject the null hypothesis and conclude the means are different.
A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled and the average error from the industry standard is measured in millimeters. The results are shown on the table. The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but are assumed equal. If we test the null hypothesis at the 1% level of significance, what is the decision?
0.0164
A recent study focused on the number of times men and women send a Twitter message in a day. The sample information is summarized below. We want to know if, at the .01 significance level, is there a difference in the mean number of times men and women send a Twitter message in a day. What is the p-value for this hypothesis test?
7.7
A survey of property owners opinions about a street-widening project was taken to determine if owners opinions were related to the distance between their home and the street. A randomly selected sample of 100 property owners was contacted and the results are shown. What is the expected frequency for people who are undecided about the project and have property front-footage between 45 and 120 feet?
False
For a contingency table, the expected frequency for a cell is found by dividing the row total by the grand total.
Strong
If the correlation between two variables is close to one, the association between the variables is ___________.
Do not reject the null hypothesis.
Suppose we test H0: the population proportion1 equal the population proportion2 at the 0.05 level of significance. If the z-test statistic is -1.07, what is our decision?
0
The results of a mathematics placement exam at two different campuses of Mercy College follow: Given that the two population standard deviations are known, what is the p-value?
True
The standard error of estimate measures the accuracy of a prediction.
25
Two samples, one of size 14 and the second of size 13, are selected to test the difference between two population means. How many degrees of freedom are used to find the critical value? Assume the population standard deviations are equal.
Fail to reject the null hypothesis.
A company is researching the effectiveness of a new website design to decrease the time to access a website. Five website users were randomly selected, and their times (in seconds) to access the website with the old and new designs were recorded. To compare the times, they computed (new website design time - old website design time). The results follow. For a 0.01 significance level, what is the decision regarding the hypothesis that the training was effective in improving customer relationships?
H0: µd ≥ 0
A company is researching the effectiveness of a new website design to decrease the time to access a website. Five website users were randomly selected, and their times (in seconds) to access the website with the old and new designs were recorded. To compare the times, they computed (new website design time - old website design time). The results follow. What is the null hypothesis?
2.256
A company is researching the effectiveness of a new website design to decrease the time to access a website. Five website users were randomly selected, and their times (in seconds) to access the website with the old and new designs were recorded. To compare the times, they computed (new website design time - old website design time). The results follow. What is the value of the test statistic?
13.277
A distributor of personal computers has five locations in a city. In the years first quarter, the sales in units are shown: For a goodness-of-fit test that sales were the same for all locations, what is the critical value at the 0.01 level of risk?
1.0 and 2.0
A frequency distribution has a mean of 200 and a standard deviation of 20. The class limits for one class are 220 up to 240. What are the standard normal z-statistics for the class limits?
A two-sample test of means
A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled and the average error from the industry standard is measured in millimeters. The results are shown on the table The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but are assumed equal. This example is what type of test?
-3.299
A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled and the average error from the industry standard is measured in millimeters. The results are shown on the table. The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but are assumed equal. What is the computed value of t?
H1: µA ≠ µB
A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled and the average error from the industry standard is measured in millimeters. The results are shown on the table. The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but assumed equal. What is the alternate hypothesis?
±2.797
A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled and the average error from the industry standard is measured in millimeters. The results are shown on the table. The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but assumed equal. What is the critical t value at the 1% level of significance?
11.07
A personnel manager is concerned about absenteeism. She decides to sample employee records to determine if absenteeism is distributed evenly throughout the six-day workweek. The null hypothesis is: Absenteeism is distributed evenly throughout the week. The 0.01 level is to be used. The sample results are shown. What is the critical value of chi-square with ? equal 0.05?
Observed frequencies
A personnel manager is concerned about absenteeism. She decides to sample employee records to determine if absenteeism is distributed evenly throughout the six-day workweek. The null hypothesis is: Absenteeism is distributed evenly throughout the week. The 0.01 level is to be used. The sample results are:
4
A question has these possible responses: excellent, very good, good, fair, and unsatisfactory. What are the degrees of freedom for a goodness-of-fit test to test the hypothesis that responses are uniformly distributed?
1.318
A recent study focused on the amount of money single men and women save monthly. The information is summarized next. Assume that the population standard deviations are equal. The researcher want to know if, at the .01 significance level, do women save more money than men. What is the value of the test statistic for this hypothesis test?
Fail to reject the null hypothesis.
A recent study focused on the number of times men and women send a Twitter message in a day. The information is summarized next. At the .01 significance level, and testing if there a difference in the mean number of times men and women send a Twitter message in a day. Based on the p-value, what is your conclusion?
2.4
A recent study focused on the number of times men and women send a Twitter message in a day. The information is summarized next. At the .01 significance level, testing if there a difference in the mean number of times men and women send a Twitter message in a day. What is the value of the test statistic for this hypothesis test?
Social activity and education are related.
A recent study of the relationship between social activity and education for a sample of corporate executives showed the following results. Based on the analysis, what can be concluded?
Chi-square statistic
A recent study of the relationship between social activity and education for a sample of corporate executives showed the following results. The appropriate test statistic for the analysis is a(n) __________.
A contingency table analysis
A recent study of the relationship between social activity and education for a sample of corporate executives showed the following results. The appropriate test to analyze the relationship between social activity and education is __________.
There is no relationship between social activity and education
A recent study of the relationship between social activity and education for a sample of corporate executives showed the following results. The null hypothesis for the analysis is __________________________.
83.67
A recent study of the relationship between social activity and education for a sample of corporate executives showed the following results. What is the value of the chi-square test statistic?
Number of contacts
A sales manager for an advertising agency believes that there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned. What is the independent variable?
H1: the population prportion A > the population proportion C
A sample of 250 adults tried the new multigrain cereal Wow! A total of 187 rated it as excellent. In a sample of 100 children, 66 rated it as excellent. Using the 0.1 significance level, the researcher wishes to show that adults like the cereal better than children. Which of the following is the alternate hypothesis?
4
A survey of property owners opinions about a street-widening project was taken to determine if owners opinions were related to the distance between their home and the street. A randomly selected sample of 100 property owners was contacted and the results are shown. How many degrees of freedom are there?
7.779
A survey of property owners opinions about a street-widening project was taken to determine if owners opinions were related to the distance between their home and the street. A randomly selected sample of 100 property owners was contacted and the results are shown. What is the critical value at the 10% level of significance?
9.488
A survey of property owners opinions about a street-widening project was taken to determine if owners opinions were related to the distance between their home and the street. A randomly selected sample of 100 property owners was contacted and the results are shown. What is the critical value at the 5% level of significance?
10
A survey of property owners opinions about a street-widening project was taken to determine if owners opinions were related to the distance between their home and the street. A randomly selected sample of 100 property owners was contacted and the results are shown. What is the expected frequency for people who are in favor of the project and have less than 45 feet of property foot-frontage?
A paired t-test.
Accounting procedures allow a business to evaluate its inventory costs based on two methods: LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in $000s) for five products with the LIFO and FIFO methods. To analyze the difference, they computed (FIFO - LIFO) for each product. Based on the following results, and testing if he LIFO method result in a lower cost of inventory than the FIFO method. This example is what type of test?
+2.132
Accounting procedures allow a business to evaluate their inventory costs based on two methods: LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in $000s) for five products with the LIFO and FIFO methods. To analyze the difference, they computed (FIFO - LIFO) for each product. Based on the following results, and testing if the LIFO method result in a lower cost of inventory than the FIFO method. If you use the 5% level of significance, what is the critical t value?
4
Accounting procedures allow a business to evaluate their inventory costs based on two methods: LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in $000s) for five products with the LIFO and FIFO methods. To analyze the difference, they computed (FIFO - LIFO) for each product. Based on the following results, and testing if the LIFO method result in a lower cost of inventory than the FIFO method. What are the degrees of freedom?
H0: µd ≤ 0
Accounting procedures allow a business to evaluate their inventory costs based on two methods: LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in $000s) for five products with the LIFO and FIFO methods. To analyze the difference, they computed (FIFO - LIFO) for each product. Based on the following results, testing if the LIFO method result in a lower cost of inventory than the FIFO method. What is the null hypothesis?
Reject the null hypothesis and conclude that the training was effective.
An investigation of the effectiveness of a training program to improve customer relationships included a pre-training and post-training customer survey. To compare the differences they computed (post-training survey score - pre-training survey score). Seven customers were randomly selected and completed both surveys. The results follow. For a 0.05 significance level, what is the decision regarding the hypothesis that the training was effective in improving customer relationships?
2.542
An investigation of the effectiveness of a training program to improve customer relationships included a pre-training and post-training customer survey. To compare the differences they computed (post-training survey score - pre-training survey score). Seven customers were randomly selected and completed both surveys. The results follow. What is the value of the test statistic?
1.943
An investigation of the effectiveness of a training program to improve customer relationships included a pre-training and post-training customer survey. To compare the differences, they computed (post-training survey score - pre-training survey score). Seven customers were randomly selected and completed both surveys. The results follow. For a 0.05 significance level, what is the critical value?
A paired t-test
An investigation of the effectiveness of a training program to improve customer relationships included a pre-training and post-training customer survey. To compare the differences, they computed (post-training survey score - pre-training survey score). Seven customers were randomly selected and completed both surveys. The results follow. This analysis is an example of _____________.
When X = 0, Y = 10.
Assume the least squares equation is Y = 10 + 20X. What does the value of 10 in the equation indicate?
The sum of two population variances
Assuming the population variances are known, the population variance of the difference between two means is _____________.
H1: the population proportion not equal 0.41
Based on the Nielsen ratings, the local CBS affiliate claims its 11 p.m. newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening news on this local CBS station. What is the alternate hypothesis?
+/-2.576
Based on the Nielsen ratings, the local CBS affiliate claims its 11 p.m. newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening news on this local CBS station. What is the critical value if ? equal 0.01?
t distribution with df = 80.
Consider independent simple random samples that are taken to test the difference between the means of two populations. The variances of the populations are unknown, but are assumed to be equal. The sample sizes of each population are n1 = 37 and n2 = 45. The appropriate distribution to use is the:
True
Correlation analysis is a statistical technique used to measure the strength of the relationship between two variables.
n1 = 11; n2 = 13
For a hypothesis test comparing two population means, the combined degrees of freedom are 24. Which of the following statements about the two sample sizes is NOT true? Assume the population standard deviations are equal.
11.345
For people released from prison, the following table shows their adjustment to civilian life and place of residence. What is the critical value for this contingency table at the 0.01 level of significance?
94% of the total variation of the dependent variable is explained by the independent variable.
If the coefficient of determination is 0.94, what can we say about the relationship between two variables?
0.4225
If the correlation coefficient (r) = 0.65, what does the coefficient of determination equal?
The variables are not related.
If the correlation coefficient between two variables, X and Y, equals zero, what can be said of the variables X and Y?
must be positive.
If the correlation coefficient has a negative value, then the coefficient of determination:
It is not zero.
If we reject the null hypothesis, what can we conclude about the population correlation coefficient?
Difference between the observed and expected frequencies is significantly large
In a goodness-of-fit test, the null hypothesis (no difference between sets of observed and expected frequencies) is rejected when the ________________.
H1: the population proportion1 > the population proportion2
In a market test of a new chocolate raspberry coffee, a poll of 400 people (sample 1) from Dobbs Ferry showed 250 preferred the new coffee. In Irvington, 170 out of 350 people (sample 2) preferred the new coffee. To test the hypothesis that a higher proportion of people in Dobbs Ferry prefer the new coffee, what is the alternate hypothesis?
the addition of "1" to the quantity under the radical sign
In regression, the difference between the confidence interval and prediction interval formulas is ________________.
True
In testing the difference between two population proportions, we pool the two sample proportions to estimate the population proportion.
True
In the goodness-of-fit test, the chi-square distribution is used to determine how well an observed distribution of observations fits an expected distribution of observations.
H0: p > 0.45 H1: p is less than or equal to 0.45
In the past five years, 45% of the tourists who visited Orlando, Florida, went to see local attractions. The city council recently spent a significant amount of money on advertising and promoting visits to area attractions. They are interested in knowing whether the advertising campaign was effective�whether it increased the proportion of tourists visiting local attractions. The proper set of hypotheses is ________________.
The independent variable
In the regression equation, what does the letter "X" represent?
The Y-intercept
In the regression equation, what does the letter "a" represent?
The slope of the line
In the regression equation, what does the letter "b" represent?
0.0336
Manufacturer 1 n1 = 81 x1 = $15.80 o1 = $3.00 Manufacturer 2 n1 = 64 x1 = $15.00 o1 = $2.25 Use the following table to determine whether or not there is a significant difference between the average hourly wages at two manufacturing companies. The p-value is ______.
Fail to reject the null hypothesis
Men: Sample Size: 25 Sample Mean: 23 Population St. Dev: 5 Women Sample Size: 30 Sample Mean: 28 Population St. Dev: 10 A recent study focused on the amount of money single men and women save monthly. The information is summarized next. Assume that the population standard deviations are equal. At the .01 significance level, what is the conclusion about the way women and men save?
z-statistic
Men: Sample Size: 25 Sample Mean: 23 Population St. Dev: 5 Women Sample Size: 30 Sample Mean: 28 Population St. Dev: 10 A recent study focused on the amount of money single men and women save monthly. The information is summarized next. Assume that the population standard deviations are equal. The question is, at the .01 significance level, do women save more money than men. What is the test statistic for this hypothesis?
2.369
Men: Sample Size: 25 Sample Mean: 23 Population St. Dev: 5 Women Sample Size: 30 Sample Mean: 28 Population St. Dev: 10 A recent study focused on the amount of money single men and women save monthly. The information is summarized next. Assume that the population standard deviations are equal. The question is, at the .01 significance level, do women save more money than men? What is the critical value for this hypothesis test?
3.841
Recently, students in a marketing research class were interested in the driving behavior of students. Specifically, the marketing students were interested in finding out if exceeding the speed limit was related to social activity. They collected the following responses from 100 randomly selected students: Using 0.05 as the significance level, what is the critical value for the test statistic?
9.89
Recently, students in a marketing research class were interested in the driving behavior of students. Specifically, the marketing students were interested in finding out if exceeding the speed limit was related to social activity. They collected the following responses from 100 randomly selected students: What is the value of the test statistic?
Driving behavior and gender are related.
Recently, students in a marketing research class were interested in the driving behavior of students. Specifically, the marketing students were interested in finding out if exceeding the speed limit was related to social activity. They collected the following responses from 100 randomly selected students; Based on the analysis, what can be concluded?
9
Sample Size (n): 81 (Bachelor's) 49 (Associates) Sample Mean Salary (in $1,000): 60 (Bachelors) 51 (Associates) Population Variance: 175 (Bachelors) 90 (Associates) The following table shows sample salary information for employees with bachelor's and associate degrees for a large company in the Southeast United States. The point estimate of the difference between the means of the two populations is ______.
False
Some important uses of the chi-square include testing for the association of two categorical variables.
150
Students were sampled in order to determine their support for the legalization of gambling in their community. A sample of 150 students were asked whether or not they supported legalization of gambling, and the following results were obtained. The number of degrees of freedom associated with this scenario is _____.
4
Students were sampled in order to determine their support for the legalization of gambling in their community. A sample of 150 students were asked whether or not they supported legalization of gambling, and the following results were obtained. The value of the chi-square test statistic equals _____.
Degrees of freedom increase
The chi-square distribution becomes more symmetrical as the ____________.
Positively skewed
The chi-square distribution is _____________.
True
The chi-square distribution is positively skewed.
Is greater than or equal to zero
The chi-square statistic _______________.
A uniform distribution
The chi-square statistic has __________.
True
The chi-square test statistic used in a goodness-of-fit test has k - 1 degrees of freedom..
Squared
The computed chi-square value is positive because the difference between the observed and expected frequencies is _____________.
22.5
The contingency table for a sample of corporate executives classified by educational level and the social activity follows. What does the expected frequency for the above average social activity and high school education equal?
1.782
The net weights (in grams) of a sample of bottles filled by a machine manufactured by Edne, and the net weights of a sample filled by a similar machine manufactured by Orno, Inc., are shown on the table: Testing the claim at the 0.05 level that the mean weight of the bottles filled by the Orno machine is greater than the mean weight of the bottles filled by the Edne machine, what is the critical value? Assume equal standard deviations for both samples.
False
The pooled estimate of the proportion is found by dividing the total number of samples by the total number of successes.
True
The regression equation is used to estimate a value of the dependent variable Y based on a selected value of the independent variable X.
x/n
The sample proportion is defined as _________.
True
The shape of the chi-square distribution depends on the number of degrees of freedom.
False
The shape of the chi-square distribution depends on the size of the sample.
False
The strength of the correlation between two variables depends on the sign of the coefficient of correlation.
False
The use of the chi-square statistic would be permissible in the following goodness-of-fit test.
can be equal to the value of the coefficient of determination (r2).
The value of the correlation coefficient (r):
False
The variance of the chi-square distribution is equal to one.
True
There is not one, but a family of chi-square distributions. There is a chi-square distribution for 1 degree of freedom, another for 2 degrees of freedom, another for 3 degrees of freedom, and so on.
That there is no preference between the colors
Three new colors have been proposed for the Jeep Grand Cherokee vehicle. They are silvered-blue, almond, and willow green. The null hypothesis for a goodness-of-fit test would be _______________.
Standard normal distribution
To test if an observed frequency distribution with five classes is normally distributed, we compute probabilities for each class based on a(n) _________________.
Convert the class limits to standard normal z-statistics
To test if an observed frequency distribution with five classes is normally distributed, we need to ___________.
The expected, normally distributed class frequencies
To test if an observed frequency distribution with five classes is normally distributed, we need to find ___________________.
Do not reject it.
To test the hypothesis that 55% of those families who plan to purchase a vacation residence in Florida want a condominium, the null hypothesis is the population proportion equal 0.55 and the alternate is the population proportion not equal .55. A random sample of 400 families who planned to buy a vacation residence revealed that 228 families want a condominium. What decision should be made regarding the null hypothesis using the 0.01 level of significance?
True
To test the null hypothesis that a set of sample data is normally distributed, we compare an expected normal distribution of the data to an observed distribution of the data.
A paired t-test
Twenty randomly selected statistics students were given 15 multiple-choice questions and 15 open-ended questions, all on the same material. The professor was interested in determining if students scored higher on the multiple-choice questions. This experiment is an example of ________________.
0.8
Use the following table to determine whether or not there is a significant difference between the average hourly wages at two manufacturing companies. What is the point estimate of the difference between the means?
3.747
User Old Website Design New Website Design A ; 30 ; 25 B ; 45 ; 30 C ; 25 ; 20 D ; 32 ; 30 E ; 28 ; 27 A company is researching the effectiveness of a new website design to decrease the time to access a website. Five website users were randomly selected, and their times (in seconds) to access the website with the old and new designs were recorded. To compare the times, they computed (new website design time - old website design time). The results follow. For a 0.01 significance level, what is the critical value?
H1: µd < 0
User Old Website Design New Website Design A ; 30 ; 25 B ; 45 ; 30 C ; 25 ; 20 D ; 32 ; 30 E ; 28 ; 27 A company is researching the effectiveness of a new website design to decrease the time to access a website. Five website users were randomly selected, and their times (in seconds) to access the website with the old and new designs were recorded. To compare the times, they computed (new website design time - old website design time). The results follow. What is the alternative hypothesis?
A significant positive relationship exists between the variables.
Using the following information: The regression analysis can be summarized as follows:
91.80%
Using the following information: What is the coefficient of determination? Round the percentage to one decimal point.
11.6985
Using the following information: What is the standard error of the estimate?
Do not reject the null hypothesis.
What is our decision for a goodness-of-fit test with a computed chi-square value of 1.273 and a critical value of 13.388?
H1: β ≠ 0
What is the alternate hypothesis to test the significance of the slope in a regression equation?
A scatter diagram
What is the chart called when the paired data (the dependent and independent variables) are plotted?
11.07
What is the critical value at the 0.05 level of significance for a goodness-of-fit test if there are six categories?
Fail to reject the null hypothesis; the difference is probably due to sampling error.
What is the decision regarding the differences between the observed and expected frequencies if the critical value of chi-square is 9.488 and the computed chi-square value is 6.079?
H0: β = 0
What is the null hypothesis to test the significance of the slope in a regression equation?
0% to 100% inclusive
What is the range of values for the coefficient of determination?
t-statistic
What is the test statistic to test the significance of the slope in a regression equation?
Independent variable
What is the variable used to predict another variable called?
The confidence interval is narrower than a prediction interval
When comparing the 95% confidence and prediction intervals for a given regression analysis ______________.
t-statistic.
When determining how well an observed set of frequencies fit an expected set of frequencies, what is the test statistic?
Standard deviation of the differences
When testing the difference between two dependent population means, the test statistic is based on a ______________.
The population variances are assumed equal but unknown
When testing the difference between two population means, the sample variances are pooled to estimate the population variance when ________________.
H0: µ1 - µ2 = 0
When testing the hypothesized equality of two population means, the implied null hypothesis is ____________.
The distribution with 15 degrees of freedom.
Which chi-square distribution would be closest to a normal distribution?
The two population standard deviations must be known.
Which condition must be met to conduct a test for the difference in two sample means using a z-statistic?
They both use the standard error of estimate.
Which of the following are the same between a confidence interval and a prediction interval?
All of them
Which of the following are true assumptions underlying linear regression? (1) For each value of X, there is a group of Y values that is normally distributed. (2) The means of these normal distributions of Y values all lie on the regression line. (3) The standard deviations of these normal distributions are equal.
The data are measured with a nominal or ordinal scale.
Which of the following assumptions is necessary to apply a goodness-of-fit test?
A contingency table analysis
Which of the following can be used to test the hypothesis that two nominal variables are related?
It is a measure of the accuracy of the prediction.
Which of the following is true about the standard error of estimate?
The shape of the distribution is based on the degrees of freedom.
Which of the following statements is correct regarding the chi-square distribution?
-0.8
Which value of the correlation coefficient indicates a stronger correlation than 0.40?
True
A scatter diagram is a graph that portrays the correlation between a dependent variable and an independent variable.
False
A t-statistic is useful for computing an expected normal distribution.
computing the log of all values of the dependent and independent variable.
An example of a way to rescale a variable to create a linear relationship is:
H0: the population proportion1 equal the population proportion2
In a market test of a new chocolate raspberry coffee, a poll of 400 people from Dobbs Ferry showed 250 preferred the new coffee. In Irvington, 170 out of 350 people preferred the new coffee. To test the hypothesis that there is no difference in preferences between the two villages, what is the null hypothesis?
Independent variable
In regression analysis, what is the predictor variable called?
It is the predicted value of Y, given a specific X value.
In the equation, Ŷ = a + bX, what is Ŷ?
True
The values of a and b in the regression equation are called the regression coefficients.
Y = a + (bX)
What is the general form of the regression equation?
-1.0 to +1.0 inclusive
What is the range of values for a coefficient of correlation?
True
A confidence interval can be determined for the mean value of Y for a given value of X.
H0: µA = µB
A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled and the average error from the industry standard is measured in millimeters. The results are presented on the table shown. The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but are assumed equal. What is the null hypothesis?
24
A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled and the average error from the industry standard is measured in millimeters. The results are shown on the table. The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but are assumed equal. What are the degrees of freedom?
8
A personnel manager is concerned about absenteeism. She decides to sample employee records to determine if absenteeism is distributed evenly throughout the six-day workweek. The null hypothesis is: Absenteeism is distributed evenly throughout the week. The 0.01 level is to be used. The sample results are shown. What is the calculated value of chi-square?
10
A personnel manager is concerned about absenteeism. She decides to sample employee records to determine if absenteeism is distributed evenly throughout the six-day workweek. The null hypothesis is: Absenteeism is distributed evenly throughout the week. The 0.01 level is to be used. The sample results are shown. What is the expected frequency?
5
A personnel manager is concerned about absenteeism. She decides to sample employee records to determine if absenteeism is distributed evenly throughout the six-day workweek. The null hypothesis is: Absenteeism is distributed evenly throughout the week. Use the 0.01 level of significance. The sample results are shown. How many degrees of freedom are there?
4
A recent study of the relationship between social activity and education for a sample of corporate executives showed the following results. The degrees of freedom for the analysis are __________.
9.488
A recent study of the relationship between social activity and education for a sample of corporate executives showed the following results. Using 0.05 as the significance level, what is the critical value for the test statistic?
0.9754
A sales manager for an advertising agency believes that there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned. A regression ANOVA shows the following results: What is the value of the coefficient of correlation?
-12.201
A sales manager for an advertising agency believes that there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned. A regression analysis shows the following results: What is the Y-intercept of the linear equation?
2.195
A sales manager for an advertising agency believes that there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned. A regression analysis shows the following results: What is the slope of the linear equation?
0.176
A sales manager for an advertising agency believes that there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned. A regression analysis shows the following results: What is the standard error of the slope?
Amount of sales dollars
A sales manager for an advertising agency believes that there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned. What is the dependent variable?
3
A sample of 100 production workers is obtained. The workers are classified by gender (male, female) and by age (under 20, 20-29, 30-39, and 40 or over). How many degrees of freedom are there?
0.723
A sample of 250 adults tried the new multigrain cereal Wow! A total of 187 rated it as excellent. In a sample of 100 children, 66 rated it as excellent. Using the 0.1 significance level, the researcher wishes to show that adults like the cereal better than children. What is the pooled proportion?
A z-statistic
A sample of 250 adults tried the new multigrain cereal Wow! A total of 187 rated it as excellent. In a sample of 100 children, 66 rated it as excellent. Using the 0.1 significance level, the researcher wishes to show that adults like the cereal better than children. What test statistic should we use to compare the ratings of adults and children?
3.9
A survey of property owners opinions about a street-widening project was taken to determine if owners opinions were related to the distance between their home and the street. A randomly selected sample of 100 property owners was contacted and the results are shown next. What is the expected frequency for people against the project and who have over 120 feet of property foot-frontage?
Fail to reject null hypothesis
Accounting procedures allow a business to evaluate its inventory costs based on two methods: LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in $000s) for five products with the LIFO and FIFO methods. To analyze the difference, they computed (FIFO - LIFO) for each product. Based on the following results, and testing if the LIFO method result in a lower cost of inventory than the FIFO method. What is the decision at the 5% level of significance?
H0: µd ≥ 0
Accounting procedures allow a business to evaluate their inventory costs based on two methods: LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in $000s) for five products with the LIFO and FIFO methods. To analyze the difference, they computed (FIFO - LIFO) for each product. Based on the following results, the question if the LIFO method results in a lower cost of inventory than the FIFO method. What is the alternate hypothesis?
True
An economist is interested in predicting the unemployment rate based on gross domestic product. Since the economist is interested in predicting unemployment, the independent variable is gross domestic product.
We cannot determine if the 2% is a significant difference.
An electronics retailer believes that, at most, 40% of their cell phone inventory was sold during November. The retailer surveyed 80 dealers and found that 38% of the inventory was sold. Since 38% is less than 40%, is this difference of 2 percentage points sampling error or a significant difference? Test at the 0.05 level. The computed z equal -0.37.
+/-1.645
Based on the Nielsen ratings, the local CBS affiliate claims its 11 p.m. newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening news on this local CBS station. What is the critical value if the level of significance is 0.10?
H0: the population proportion equal 0.41
Based on the Nielsen ratings, the local CBS affiliate claims its 11 p.m. newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening news on this local CBS station. What is the null hypothesis?
0.36
Based on the Nielsen ratings, the local CBS affiliate claims its 11 p.m. newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening news on this local CBS station. What is the sample proportion?
-1.02
Based on the Nielsen ratings, the local CBS affiliate claims its 11 p.m. newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening news on this local CBS station. What is the z test statistic?
Fail to reject the null hypothesis.
Based on the Nielsen ratings, the local CBS affiliate claims its 11 p.m. newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening news on this local CBS station. What is your decision if ? equal 0.01?
Predict the value of the dependent variable given a value of the independent variable
Based on the regression equation, we can _______________.
True
Because the coefficient of determination is expressed as a percent, its value is between 0% and 100%.
H1: µ1 > µ2
Campus Sample Size Mean Pop. St. Dev 1 ; 330 ; 33 ; 8 2 ; 310 ; 31 ; 7 The results of a mathematics placement exam at two different campuses of Mercy College follow: What is the *alternative hypothesis* if we want to test the hypothesis that the mean score on Campus 1 is higher than on Campus 2?
H0: µ1 ≤ µ2
Campus Sample Size Mean Pop. St. Dev 1 ; 330 ; 33 ; 8 2 ; 310 ; 31 ; 7 The results of a mathematics placement exam at two different campuses of Mercy College follow: What is the *null hypothesis* if we want to test the hypothesis that the mean score on Campus 1 is higher than on Campus 2?
0.0324
Consider a regression analysis, where the correlation coefficient is 0.18. Then, the coefficient of determination is _______.
Related
For a chi-square test involving a contingency table, suppose the null hypothesis is rejected. We conclude that the two variables are __________.
True
For a goodness-of-fit test, the following are possible null and alternate hypotheses: H0: Sales are uniformly distributed among the five locations. H1: Sales are not uniformly distributed among the five locations.
1.711
For a hypothesis comparing two population means, H0: μ1 ≤ μ2, what is the critical value for a one-tailed hypothesis test, using a 5% significance level, with both sample sizes equal to 13? Assume the population standard deviations are equal.
k - 1
For any chi-square goodness-of-fit test, the number of degrees of freedom is found by ______.
4,601
Given the least squares regression equation, Ŷ = 1,202 + 1,133X, when X = 3, what does Ŷ equal?
pc
How is a pooled estimate of the population proportion represented?
0.4
If 20 out of 50 students sampled live in a college dormitory, what is the estimated proportion of students at the University living in a dormitory?
0
If all the plots on a scatter diagram lie on a straight line, what is the standard error of estimate?
H1: the population proportion1 not equal the population proportion2; z > +1.960 and z < -1.960
If the decision is to reject the null hypothesis of no difference between two population proportions at the 5% level of significance, what are the alternative hypothesis and rejection region?
±2.17
If the null hypothesis that two means are equal is true, where will 97% of the computed z values lie between?
False
If we are testing the difference between two population proportions, it is assumed that the two populations are approximately normal and have equal variances.
False
In regression analysis, error is defined as the difference between the measured value, Y, and the predicted Y value,
rescaling the variables.
In regression, if the relationship between the dependent and independent variables is non-linear, a linear relationship between the variables can be achieved by:
That Y increases by 20 units for each unit increase in X
In the least squares equation, Ŷ = 10 + 20X, the value of 20 indicates ____________.
The dependent variable
In the regression equation, what does the letter "Y" represent?
Fail to reject the null.
It is claimed that in a bushel of peaches, less than 10% are defective. A sample of 400 peaches is examined and 50 are found to be defective. If ? equal 0.025, what will be the decision?
H1: the population proportion < 0.10
It is claimed that in a bushel of peaches, less than 10% are defective. A sample of 400 peaches is examined and 50 are found to be defective. What is the alternate hypothesis for a one-sided test?
-1.96
It is claimed that in a bushel of peaches, less than 10% are defective. A sample of 400 peaches is examined and 50 are found to be defective. What is the critical value for ? equal 0.025?
H0: the population proportion greater than or equal to 0.10
It is claimed that in a bushel of peaches, less than 10% are defective. A sample of 400 peaches is examined and 50 are found to be defective. What is the null hypothesis?
0.125
It is claimed that in a bushel of peaches, less than 10% are defective. A sample of 400 peaches is examined and 50 are found to be defective. What is the sample proportion?
1.667
It is claimed that in a bushel of peaches, less than 10% are defective. A sample of 400 peaches is examined and 50 are found to be defective. What is the z-test statistic?
True
Nonparametric tests require no assumptions about the shape of the population distribution.
False
One assumption underlying linear regression is that the X values are normally distributed.
+0.933
Product FIFO LIFO 1 ; 225 ; 221 2 ; 119 ; 100 3 ; 100 ; 113 4 ; 212 ; 200 5 ; 248 ; 245 Accounting procedures allow a business to evaluate its inventory costs based on two methods: LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in $000s) for five products with the LIFO and FIFO methods. To analyze the difference, they computed (FIFO - LIFO) for each product. Based on the following results, and testing if the LIFO method result in a lower cost of inventory than the FIFO method. What is the value of calculated t?
There is no relationship between gender and speeding
Recently, students in a marketing research class were interested in the driving behavior of students. Specifically, the marketing students were interested in finding out if exceeding the speed limit was related to gender. They collected the following responses from 100 randomly selected students. The null hypothesis for the analysis is ____________.
1
Recently, students in a marketing research class were interested in the driving behavior of students. Specifically, the marketing students were interested in finding out if exceeding the speed limit was related to social activity. They collected the following responses from 100 randomly selected students. The degrees of freedom for the analysis are ________.
testing for goodness-of-fit.
Some important uses of the chi-square distribution include:
an interval or ratio scale
The Pearson product-moment correlation coefficient, r, requires that variables be measured with _____________.
Do not reject the null hypothesis because -0.879 lies in the region between +2.326 and -2.326.
The claim that 40% of those persons who retired from an industrial job before the age of 60 would return to work if a suitable job was available is to be investigated at the 0.02 significance level. If 74 out of the 200 workers sampled said they would return to work, what is our decision?
False
The claim that male and female students at Coastal Carolina University prefer different parking lots on campus is an example of a chi-square null hypothesis.
True
The coefficient of determination is the proportion of total variation in Y that is explained by X.
False
The coefficient of determination is the square root of the coefficient of correlation.
10
The degrees of freedom for a contingency table with 6 rows and 3 columns is ______.
Contingency table
The following table classifies 100 individuals using two variables, gender and college attended. What is this two-way classification called?
False
The hypothesis to test the slope of a regression equation is H0: ? = 0.
True
The least squares technique minimizes the sum of the squares of the vertical distances between the actual Y values and the predicted values of Y.
n and the population proportion
The number of trials and the population proportion are respectively represented by what symbols?
3.37
The results of a mathematics placement exam at two different campuses of Mercy College follow: What is the computed value of the test statistic?
0.9583
Using the following information: What is the correlation coefficient?
25
We test for a hypothesized difference between two population means: H0: ?1 = ?2. The population standard deviations are unknown but assumed equal. The number of observations in the first sample is 15, and 12 in the second sample. How many degrees of freedom are associated with the critical value?
(Rows - 1) � (Columns - 1)
What are the degrees of freedom for a contingency table analysis?
n - 2
What are the degrees of freedom used to test the significance of the slope in a simple linear regression equation?
The coefficient of determination is 0.49.
What does a coefficient of correlation of 0.70 infer?
0.7921
What does the coefficient of determination equal if the correlation coefficient (r) = 0.89?
When two dependent samples are compared
When is it appropriate to use the paired difference t-test?
Variables are based on the nominal measurement scale.
Which of the following statements is correct regarding the goodness-of-fit test?
It describes the relationship between two variables.
Which of the following statements regarding the coefficient of correlation is true?