Lowery bstat exam 2p2

The sum of the deviations from the mean is 1. Zero 2. The variance 3. The SD 4. The range 4. Unknown

1. ZERO

A listing os all possible outcomes of a random variable along with the corresponding probabilities of occurrence is called a 1. Random variable 2. Probability Distribution 3. Population 4. Sample 5. None of the above

2. Probability Dist.

If the variance for a sample of hourly wages was compiled to be $25, what is the standard deviation? 1. 625 2. 25 3. 5 4. 50 5. Cannot determine

3. $5

What level of measurement is needed in order to calculate the variance of a set of data? 1. Discrete 2. Ordinal 3. interval 4. ratio 5. Continuous

3. Interval

The mean, as a measure of central location would be inappropriate for which one of the following? 1. Age of adults at a senior citizen center 2. Weights of people living in GA 3. Number of pages in textbooks at a certain college 4. Marital status of college students at a certain college 5. It would be appropriate for all

4. Marital Status

Find the median 0,0,6,8,10,14

7

nonparametric statistics

A statistical method wherein the data is not required to fit a normal distribution. Often used ordinal data. Good for ranks. Inferential.

A ratio of two variances

An F test statistic is

If all the data for a regression analysis are plotted on a scatter diagram...of estimate would be: a. -1 b. +1 C. 0 d. It cannot be determined from this information

C. 0

A disadvantage of using mean to summarize a set of data is that the mean is not unique to a set of data.

Can be influenced by extreme values

What type of variable is the amount of time spent sleeping per day?

Continuous

What type of variable is the number os auto accidents reported in a given month?

Discrete

Multicollinearity

In Regression Analysis, a situation where two or more explanatory variables(Independent) are correlated.

For a data set with some variation in the data and an even number of observations, half are greater than the

Median

Education was measured as freshman, sophomore, junior, senior. Which is the level of measurement of a variable?

Ordinal

Which of the following is NOT a use of descriptive statistics?

Predicting

age is what level of measurement?

Ratio

Mode

The value that occurs most frequently in a given data set.

What is the probability of making a type 2 error if the null hypothesis is actually true? a. 1 b. 0 c. 0.025 d. It is usually 0.05

a. 0

Mileage was recorded for a sample of 100 tires. the average tread life was 50,000 miles with a standard deviation of 3,500 miles. what is the best estimate of the average read life for the population of tires? a. 50,000 b. 3,500 c. (50,000/100) d. (3,500/100) e. None of the above would provide a good estimate

a. 50,000

The weight of people is a. A continuous random variable b. A discrete random variable c. Interval data d. Ordinal data e. None of the above

a. A continuous random variable

A sample of 20 randomly selected students was given a multiple-choice test and an essay test on the same material and the scores recorded for both tests for each of the 20 students the professor was interested in determining which type of test would result in higher scores. this was an example of___ a. A one sample test of a population proportion b. A test for the difference between two population means c. A dependent samples (paired data, repeated measures) test d. A test of the differences between two population proportions

a. A dependent samples (paired data, repeated measures) test

What is a type 2 error? a. Accepting a false null hypothesis b. Rejecting a false null hypothesis c. Accepting a false alternate hypothesis d. Rejecting a false alternate hypothesis e. Rejecting a true null hypothesis

a. Accepting a false null hypothesis

If the alternate hypothesis states that U does not equal 4,000, where is the rejection region for the hypothesis test? a. Center of the distribution b. Lower or left tail of the distribution c. Upper or right tail of the distribution d. Both tails of the distribution

a. Both tails of the distribution

What kind of distribution is the t distribution? a. Continuous b. Discrete c. Sampling d. Standard Normal e. Very wide and very flat

a. Continuous

Which of the following is true? a. If the results of a hypothesis test are statistically significant, they must also have a practical significance b. The results of a hypothesis test can have statistically significance without having practical significance c. The results of a hypothesis test cannot have both statistical and practical significance d. None of the above is true

a. If the results of a hypothesis test are statistically significant, they must also have a practical significance

. What type of analysis is used to determine if there is a difference in sales between... a. One way ANOVA b. Two way ANOVA c. Regression analysis d. Correlation analysis

a. One way ANOVA

A regression equation is generally used to: a. Predict the value of the dependent variable for a given value of the independent variable b. Predict the value of the independent variable for a given value of the dependent variable c. Measure the strength of the association between two variables d. All of the above

a. Predict the value of the dependent variable for a given value of the independent variable

If the correlation between two variables is close to one, the association is? a. Strong b. Moderate c. Weak d. Nonexistent

a. Strong

A method of determining if there are differences between... a. The Kruskal-Wallis Test b. The Wilcoxon Rank-Sum test c. The wilcoxon signed rank test d. None of the above

a. The Kruskal-Wallis Test

In ANOVA, the variation that is explained by the factor is: a. The Variation between the samples b. The variation within the samples c. The error variation d. The standard error

a. The Variation between the samples

How is the t distribution different from the z distribution a. The t has more variability b. The t is a continuous distribution c. The t has a mean score of zero d. The t is a discrete distribution e. Both A and B above are differences

a. The t has more variability

Which statement is correct about the F distribution? . The values cannot be negative b. The values cannot be positive c. The values can be negative, zero, or positive d. It is negatively skewed

a. The values cannot be negative

In a simple regression analysis, if the Y intercept is positive, then: a. There is a positive relationship between X and Y b. If X is increased, Y must also increase c. If Y increased, X must also increase d. None of these alternatives is correct

a. There is a positive relationship between X and Y

A null hypothesis makes a claim about a a. Population parameter b. Sample statistic c. Sample mean d. Z-value e. Any of the above

a. population parameter

Which of the following would be used as a point estimate for the population mean? a. The sample mean b. The test statistic c. The sample standard deviation d. The population mean e. The Z Value

a. the sample mean

This of the following values would indicate a stronger association base... a. 0 b. -.97 c. .83 d. 100

b. -.97

If we choose a random starting point and then select every fifth invoice in a file, what type of sampling is being employed? a. Simple random sampling b. Systematic sampling c. Stratified random sampling d. Cluster sampling e. None of the above

b. . Systematic sampling

For a normal distribution, the mean plus and minus 2 standard deviations will include what percent of observations a. 50% b. 99.7% c. 95% d. 68% e. All of the observations

b. 95%

An F test statistic is a. A standard error b. A ratio of two variances c. The difference between two or more means d. A population parameter

b. A ratio of two variances

University officials say that a fee increase will be implemented if more than 75% of the voting student population supports the fee increase. if a sample of students revea. als a 95% confidence interval of (0.71,0.83), what conclusion can be drawn based on the interval? a. Conclude that another sample is needed, because this one was not representative b. Conclude it should not be implemented c. Conclude it should be implemented This interval does not allow any conclusion to be drawn

b. Conclude it should not be implemented

A test to determine if the mean of a population is greater than 40 resulted in a test statistic of 1.05. the sample size was 10. what is the p-value? a. Less than 0.20 b. Greater than 0.10 c. Greater than 0.20 d. 0.1469 e. None of the above

b. Greater than 0.10

If a confidence interval is too wide to be useful, what can be done? a. Increase the level of confidence bIncrease the sample size b. Increase the variability in the population c. Either A or B would be a good choice d. All of the above would be a good choice

b. Increase the sample size

During hypothesis testing, the initial assumption about the null hypothesis is that a. It is false b. It is true c. It is unknown d. No assumption is made

b. It is true

Statistical methods that do not generally make the assumption... a. Parametric methods b. Nonparametric methods c. Analysis of variance methods d. None of the above

b. Nonparametric methods

In the analysis of variable procedure (ANOVA) the "factor" might also be called: a. The dependent b. The independent c. The response variable d. The test static

b. The independent

When conducting a dependent sample, pairs data test, the sample estimate is a. One of the sample means b. The mean of the differences c. The population mean d. The sample standard deviation

b. The mean of the differences

The mean of the sample mean is a. The sample mean b. The population mean c. Unable to be determined d. Usually smaller than the population mean e. None of the above

b. The population mean

The power of a hypothesis test is a. Its ability to answer a question about a population parameter b. The probability of rejecting the null hypothesis when the null is false c. That we can make inferences about a sample mean d. None of the above are correct e. A,B,C are correct

b. The probability of rejecting the null hypothesis when the null is false

The difference between a population parameter and the sample statistic is a. At the center of a normal distribution b. Sampling error c. Usually very large d. Usually very small e. None of the above

b. sampling error

What is the relationship between the variance and the standard deviation? 1. variance is the square root of the SD 2. variance is the square of the SD 3. variance is double the sd 4. variance is half of the sd 5. no relationship

b. variance is the square of the the sd

If the coefficient of correlation equals 0.40, then which of the following will... . There is a strong relationship between the two variables b. 40% of the variation in one variable is explained by the other c. The coefficient of determination is 0.16 d. The coefficient of determination is .40

c. The coefficient of determination is 0.16

. Larger values of r^2 imply that: a. The average of the independent variable in high b. Average value of the independent variable is low c. The regression line fits the data well d. The line passes through the origin

c. The regression line fits the data well

What information is needed to find a p-value? a. Type of test and alpha level b. Alpha level and test statistic c. Type of test and test statistic d. Type of test, alpha level, and test statistic

c. Type of test and test statistic

. Which of the following is true about the standard error of estimate? a. It is also called the coefficient of error b. Is it based on squared deviations between the actual Y values and actual X values c. It can be either negative or positive d. It is based on squared deviations between the actual Y values and predicted Y values

d. It is based on squared deviations between the actual Y values and predicted Y values

The standard error is a. The standard deviation of the sample b. The standard deviation of the population c. The standard deviation of the population distribution d. The standard deviation of the sampling distribution e. Both A and D are correct

d. The standard deviation of the sampling distribution

Regarding the ANOVA procedure; the appropriate situation for making inferences about...pairs of treatment means would be a. When one way ANOVA design has been used b. When a two way ANOVA design has been used c. When the null hypothesis has not been rejected d. When the null hypothesis has been rejected

d. When the null hypothesis has been rejected

When dividing a population into groups so that a random sample of the groups can be collected, what type of sampling is used? a. Simple random sampling b. Systematic sampling c. Stratified random sampling d. Cluster sampling e. None of the above

d. cluster sampling

parametric tests

rely on assumptions regarding distribution of population and are specific to population parameters.

range

the difference between the highest and lowest scores in a distribution