Statistics Final Exam

Find the value of z such that 00.8064 of the area lies between −z and z. Round your answer to two decimal places.

1.30

Identify the population being studied.: The heights of 14 out of the 27 okra plants at Mr. Lonardo's greenhouse.

All okra plants at Mr. Lonardo's greenhouse.

Determine if there is an outlier in the given data. If yes, please state the value(s) that are considered outliers. 16,42,3,53,10,7,8,29,13,51,8,30,23,3

No outliers

Which plan has the least amount of risk? Plan A: - 25,000(0.22) - 40,000(.21) - 75,000(.57) Plan B - -25,000(.09) - 10,000(.24) - 25,000(.67)

Plan B

A care provider applies a process to produce a desired response to the .

treatment group

If you throw exactly two heads in two tosses of a coin you win $⁢33. If not, you pay me $⁢8. Step 1 of 2: Find the expected value of the proposition. Round your answer to two decimal places. Losses must be expressed as negative values.

$2.25

Consider the following data: x4 5 6 7 8 P(X=x)0.3 0.2 0.2 0.1 0.2 Step 5 of 5: Find the value of P(X>5). Round your answer to one decimal place.

0.5

If you throw exactly two heads in two tosses of a coin you win $⁢33. If not, you pay me $⁢8. Step 2 of 2: If you played this game 755 times how much would you expect to win or lose? Round your answer to two decimal places. Losses must be expressed as negative values.

1698.75

A high school has 3636 players on the football team. The summary of the players' weights is given in the box plot. What is the interquartile range of the players' weights? -158 -178 -210 -224 -254

46 pounds

Determine if the correlation between the two given variables is likely to be positive or negative, or if they are not likely to display a linear relationship. The average cost of a laptop and the attendance at a water park on a given day

No correlation

Donna is looking into investing a portion of her recent bonus into the stock market. While researching different companies, she discovers the following standard deviations of one year of daily stock closing prices. Masterful Pocketwatches: Standard deviation of stock prices =$⁢9.67 The Azure Travel Company: Standard deviation of stock prices =$⁢1.15 Based on the data and assuming these trends continue, which company would give Donna a stable long-term investment?

The Azure Travel Company the smaller standard deviation indicates that the azure travel company has less variabilty in its closing prices than masterful pocketwatches

In a experiment, only the partaker does not know whether they have been placed in the experimental or control group.

single-blind

Select the word or phrase that will correctly complete the statement. A/An is calculated by dividing the difference between a data value and the mean by the standard deviation.

z-score

Select the word or phrase that will correctly complete the statement. A/An is useful in comparing data values from populations with different means and standard deviations.

z-score

Consider the following data. −1,−4,−5,11,−2,7 Copy Data Step 2 of 3: Determine the median of the given data.

-1.5

The life of light bulbs is distributed normally. The variance of the lifetime is 225 and the mean lifetime of a bulb is 590 hours. Find the probability of a bulb lasting for at most 607 hours. Round your answer to four decimal places.

0.8708

Find the 20% trimmed mean of the following data. If necessary, round to one more decimal place than the largest number of decimal places given in the data. Lengths of Longest 3-Point Kick for NCAA Division 1-A Football. 29, 33, 37, 39, 40, 41, 42, 43, 43, 44, 45, 47, 48, 49, 52, 53, 54, 54, 55, 60

45.6

In a laboratory experiment the control group is often given a .

placebo

Determine if the numerical value describes a population parameter or a sample statistic. 66% of all students at the local university voted in the last election.

population parameter

Determine whether the statement describes a population or a sample. The heights of 5 out of the 32 okra plants at Mr. Lonardo's greenhouse.

sample

Determine whether the statement describes a population or a sample. The types of cars of a sample of 25 employees at the local news network.

sample

Determine whether the statement describes a population or a sample.: The number of times 33 out of 39 students on your floor order buffalo wings in a week.

sample

Determine if the numerical value describes a parameter or a statistic. A recent poll of 1266 corporate executives showed that the average price of their cars is $⁢45,900.

sample statistic

Suppose the following estimated regression equation was determined to predict salary based on years of experience. Estimated Salary=23,932.92+2352.69(Years of Experience) What is the estimated salary for an employee with 3 years of experience?

$30990.99

Find the area under the standard normal curve to the right of z=0.78. Round your answer to four decimal places, if necessary.

.2177

Consider the following data: x4 5 6 7 8 P(X=x)0.3 0.2 0.2 0.1 0.2 Step 4 of 5: Find the value of P(X<8). Round your answer to one decimal place.

.8

A soft drink machine outputs a mean of 28 ounces per cup. The machine's output is normally distributed with a standard deviation of 3 ounces. What is the probability of filling a cup between 25 and 34 ounces? Round your answer to four decimal places.

.8185

The table below gives the age and bone density for five randomly selected women. Using this data, consider the equation of the regression line, yˆ=b0+b1x for predicting a woman's bone density based on her age. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Step 6 of 6: Find the value of the coefficient of determination. Round your answer to three decimal places. Age 42 43 51 56 65 Bone Density 353 344 333 324 322

0.871

Consider the following data: x4 5 6 7 8 P(X=x)0.3 0.2 0.2 0.1 0.2 Step 3 of 5: Find the standard deviation. Round your answer to one decimal place.

1.4

A midsize mobile carrier keeps records of complaints received from its customers. Complaints for last month are listed in the following table. What percent of the complaints are due to the category Poor coverage? Round your answer to two decimal places, if necessary. poor coverage- 118 too expensive- 99 extra data usage charges- 87 long customer service wait times- 92 poor tech support- 106 incorrect billing- 89 insurance doesn't cover loss/theft- 43 frequently dropped calls- 156

14.94%

Find the number of outcomes in the complement of the given event. Out of 321 apartments in a complex, 134 are rented.

187

Consider the following data: x4 5 6 7 8 P(X=x)0.3 0.2 0.2 0.1 0.2 Step 1 of 5: Find the expected value E(X)E(X). Round your answer to one decimal place.

5.7

For the following type of data set, would you be more interested in looking at the mean, median, or mode? State your reasoning. The rating of professors on a scale from 1 to 5 (with 1 being the worst and 5 being the best)

Correct measure of center: mode Justification: The ratings of professors are qualitative data.

Determine whether or not the distribution is a discrete probability distribution and select the reason why or why not. x6 7 9 P (X=x) 0.17 0.18 0.35 First, decide whether the distribution is a discrete probability distribution, then select the reason for making this decision.

Decide: No Reason: Since the sum of probabilities is not equal to 1.

Determine whether the statement describes a descriptive or inferential statistic. 59% of all freshmen at your school reside on campus.

Descriptive Statistic

Determine whether the statement describes a descriptive or inferential statistic. The average number of hours students in your statistics class study per week is 17.4.

Descriptive Statistic

Determine whether the statement describes a descriptive or inferential statistic. The average price of a car at the new car dealership in town is $28,600.

Descriptive Statistic

Determine whether the statement describes a descriptive or inferential statistic.: 79% of all students at the local university voted in the last election.

Descriptive Statistic

Identify the population being studied and the sample chosen.: The heights of 4 out of the 36 pepper plants at Mr. Lonardo's greenhouse.

Population: The 36 pepper plants at Mr. Lonardo's greenhouse. Sample: The 4 pepper plants at Mr. Lonardo's greenhouse.

Determine if the correlation between the two given variables is likely to be positive or negative, or if they are not likely to display a linear relationship. An employee's level of experience and income

Positive

Classify the following data. Indicate whether the data is qualitative or quantitative, indicate whether the data is discrete, continuous, or neither, and indicate the level of measurement for the data. Fifty people were asked to respond to a survey question regarding how frequently they used their credit card. The categories they were asked to choose from are given below: 1) Infrequently 2) Sometimes 3) Frequently

Qualitative, Neither, Ordinal

Calculate the range, population variance, and population standard deviation for the following data set. If necessary, round to one more decimal place than the largest number of decimal places given in the data. 10, 9, 4, 9, 4, 3, 6, 7, 6, 29

Range: 26 Population Variance: 50.8 Population Standard Deviation: 7.1

Calculate the range, population variance, and population standard deviation for the following data set. If necessary, round to one more decimal place than the largest number of decimal places given in the data. 10,8,4,6,5,8,4,3,9,32

Range: 29 Population Variance: 64.3 Population Standard Deviation: 8

Determine if the numerical value describes a parameter or a statistic. A recent poll of 2883 home owners in West Virginia showed that the average price of their houses is $⁢321,000.

Sample Statistic

Determine if the numerical value describes a parameter or a statistic. A recent poll of 3054 corporate executives showed that the average price of their cars is $⁢49,700.

Sample Statistic

Identify the sample chosen for the study.: The number of times 12 out of 23 students on your floor order buffalo wings in a week.

The 12 students on your floor.

Identify the sample chosen for the study. The types of cars of a sample of 26 parents of your classmates.

The 26 parents of your classmates.

The following histogram represents the distribution of scores on a ten point quiz. Step 1 of 3: Which score has the highest frequency?

The bar that is the highest.

The table below gives the age and bone density for five randomly selected women. Using this data, consider the equation of the regression line, yˆ=b0+b1x for predicting a woman's bone density based on her age. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Step 4 of 6: Determine the value of the dependent variable y^ at x=0 Age 42 43 51 56 65 Bone Density 353 344 333 324 322

bo

Fill in the blank with the most appropriate term. A company did a study on the physical activity level and weight gain of its employees. Age was not considered so it might be an example of a(n) .

confounding variable

Determine whether an observational or experimental study is appropriate to address the following statement. A general manager of a restaurant wants to study if reducing prices on Tuesdays will increase profits.

experimental

Determine whether an observational or experimental study is appropriate to address the following statement.: A general manager of a restaurant wants to study if closing the store early on weeknights will hurt profits.

experimental

Determine whether the following events are mutually exclusive. Choosing a heart or a spade out of a standard deck of cards.

mutually exclusive

Find the mean, median, and mode of the following data. If necessary, round to one more decimal place than the largest number of decimal places given in the data. Rate of Fatal Alcohol Impaired Car Crashes per 100 Million Vehicle Miles of Travel: .79, .51, .52, .51, .68, .65, .79, .37, .79, .29, .57, .34, .46, .62, .63, .77, .57, .35, .30, .58

Mean: .555 Median: .57 Mode: .79

Suppose the following estimated regression equation was determined to predict salary based on years of experience. Estimated Salary=23,237.70+2277.01(Years of Experience) What is the estimated salary for an employee with 15 years of experience?

$57392.85

The table below gives the age and bone density for five randomly selected women. Using this data, consider the equation of the regression line, yˆ=b0+b1x for predicting a woman's bone density based on her age. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Step 1 of 6: Find the estimated slope. Round your answer to three decimal places. Age 42 43 51 56 65 Bone Density 353 344 333 324 322

-1.291

The table below gives the age and bone density for five randomly selected women. Using this data, consider the equation of the regression line, yˆ=b0+b1x for predicting a woman's bone density based on her age. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Step 5 of 6: Find the error prediction when x=43. Round your answer to three decimal places. Age 42 43 51 56 65 Bone Density 353 344 333 324 322

-2.044

The table below gives the list price and the number of bids received for five randomly selected items sold through online auctions. Using this data, consider the equation of the regression line, y^=b0+b1x, for predicting the number of bids an item will receive based on the list price. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Price in Dollars 30 32 43 45 50 Number of Bids 2 4 5 6 7 Step 2 of 6: Find the estimated y-intercept. Round your answer to three decimal places.

-3.656

Consider the following data. −1,−4,−5,11,−2,7 Step 1 of 3: Determine the mean of the given data.

1

Consider the following data: x4 5 6 7 8 P(X=x)0.3 0.2 0.2 0.1 0.2 Step 2 of 5: Find the variance. Round your answer to one decimal place.

2.2

A high school has 48 players on the football team. The summary of the players' weights is given in the box plot. Approximately, what is the percentage of players weighing greater than or equal to 232 pounds? 158 185 220 232 248

25

The table below gives the age and bone density for five randomly selected women. Using this data, consider the equation of the regression line, yˆ=b0+b1x for predicting a woman's bone density based on her age. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Step 3 of 6: Find the estimated value of y when x=43. Round your answer to three decimal places. Age 42 43 51 56 65 Bone Density 353 344 333 324 322

346.034

A high school has 32 players on the football team. The summary of the players' weights is given in the box plot. What is the interquartile range of the players' weights?

72

Suppose that shoe sizes of American women have a bell-shaped distribution with a mean of 8.05 and a standard deviation of 1.47. Using the empirical rule, what percentage of American women have shoe sizes that are less than 9.52? Please do not round your answer.

84%

Suppose that shoe sizes of American women have a bell-shaped distribution with a mean of 8.22 and a standard deviation of 1.48. Using the empirical rule, what percentage of American women have shoe sizes that are less than 12.66? Please do not round your answer.

99.85%

Determine whether an observational or experimental study is appropriate to address the following statement. A gift shop owner wants to study if closing the store early on weeknights will hurt profits.

Experimental

Determine if the following events are independent. Sean runs out of gas on the way to work. Liz rents a movie.

Independent

The table below gives the list price and the number of bids received for five randomly selected items sold through online auctions. Using this data, consider the equation of the regression line,y^=b0+b1x, for predicting the number of bids an item will receive based on the list price. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Price in Dollars: 30 32 43 45 50 Number of Bids: 2 4 5 6 7 Step 4 of 6: Determine if the statement "All points predicted by the linear model fall on the same line" is true or false.

True

The table below gives the list price and the number of bids received for five randomly selected items sold through online auctions. Using this data, consider the equation of the regression line,y^=b0+b1x, for predicting the number of bids an item will receive based on the list price. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Price in Dollars: 30 32 43 45 50 Number of Bids: 2 4 5 6 7 Step 5 of 6: Determine the value of the dependent variable y^ at x=0.

b0

Fill in the blank with the most appropriate term. are additional variables that were not measured but affected the outcomes in a study.

confounding variables

Determine if the numerical value describes a population parameter or a sample statistic. 52% of all freshmen at your school reside on campus.

population parameter

Determine if the numerical value describes a parameter or a statistic. A recent poll of 2935 corporate executives showed that the average price of their cars is $⁢27,100

sample statistic

Determine if the numerical value describes a parameter or a statistic.: A recent poll of 3798 corporate executives showed that the average price of their cars is $31,200.

sample statistic

Suppose that a company wishes to predict sales volume based on the amount of advertising expenditures. The sales manager thinks that sales volume and advertising expenditures are modeled according to the following linear equation. Both sales volume and advertising expenditures are in thousands of dollars. Estimated Sales Volume=48.07+0.49(Advertising Expenditures) If the company has a target sales volume of $275,000, how much should the sales manager allocate for advertising in the budget? Round your answer to the nearest dollar.

$463,122

Consider the following data representing the price of plasma televisions (in dollars). 1214, 1156, 1257, 1328, 1316, 1087, 1204, 1286, 1066, 1268, 1024, 1186, 1216, 1347, 1076, 1325, 1087, 1324, 1028, 1191, 1332 Step 2 of 4: Determine the frequency of the second class.

3

Consider the following data representing the price of plasma televisions (in dollars). 1214, 1156, 1257, 1328, 1316, 1087, 1204, 1286, 1066, 1268, 1024, 1186, 1216, 1347, 1076, 1325, 1087, 1324, 1028, 1191, 1332 Step 4 of 4: Compute the cumulative frequency of the first class.

3

Consider the following data representing the price of plasma televisions (in dollars). 1214, 1156, 1257, 1328, 1316, 1087, 1204, 1286, 1066, 1268, 1024, 1186, 1216, 1347, 1076, 1325, 1087, 1324, 1028, 1191, 1332 Step 1 of 4: Determine the class width of the classes listed in the frequency table.

60

Decide if the following statement is true or false. The population standard deviation and sample standard deviation are the same value for the same set of data.

False

A survey of 885 people revealed that 51% have a college degree; therefore it can be assumed that 51% of the U.S. population has a college degree.

Inferential Statistic

Determine whether the statement describes a descriptive or inferential statistic. A recent poll of 3412 students in Pennsylvania showed that the average number of hours a U.S. college student studies per week is 11.3.

Inferential Statistic

Determine whether the statement describes a descriptive or inferential statistic. A survey of 829 people revealed that 55% have a college degree; therefore it can be assumed that 55% of the U.S. population has a college degree.

Inferential Statistic

Three potential employees took an aptitude test. Each person took a different version of the test. The scores are reported below. Tera got a score of 79.7; this version has a mean of 66.2 and a standard deviation of 9. Norma got a score of 258; this version has a mean of 244 and a standard deviation of 28. Kerri got a score of 8.71; this version has a mean of 7 and a standard deviation of 0.9. If the company has only one position to fill and prefers to fill it with the applicant who performed best on the aptitude test, which of the applicants should be offered the job?

Kerri

Consider the following data. −1,−4,−5,11,−2,7 Copy Data Step 3 of 3: Determine if the data set is unimodal, bimodal, multimodal, or has no mode. Identify the mode(s), if any exist.

No mode

The table below gives the list price and the number of bids received for five randomly selected items sold through online auctions. Using this data, consider the equation of the regression line, y^=b0+b1x, for predicting the number of bids an item will receive based on the list price. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Price in Dollars 30 32 43 45 50 Number of Bids 2 4 5 6 7 Step 1 of 6: Find the estimated slope. Round your answer to three decimal places.

0.211

Consider the following data representing the price of plasma televisions (in dollars). 1214, 1156, 1257, 1328, 1316, 1087, 1204, 1286, 1066, 1268, 1024, 1186, 1216, 1347, 1076, 1325, 1087, 1324, 1028, 1191, 1332 Step 3 of 4: Calculate the relative frequency of the second class. Determine your answer as a simplified fraction.

1 over 7

What is the probability of rolling a sum of 5 on a standard pair of six-sided dice? Express your answer as a fraction or a decimal number rounded to three decimal places, if necessary.

1 over 9

The table below gives the age and bone density for five randomly selected women. Using this data, consider the equation of the regression line, yˆ=b0+b1x for predicting a woman's bone density based on her age. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Step 2 of 6: Find the estimated y-intercept. Round your answer to three decimal places. Age 42 43 51 56 65 Bone Density 353 344 333 324 322

401.547

A manufacturer makes bags of popcorn and bags of potato chips. The average weight of a bag of popcorn is supposed to be 3.08 ounces with an allowable deviation of 0.03 ounces. The average weight of a bag of potato chips is supposed to be 5.08 ounces with an allowable deviation of 0.02 ounces. A factory worker randomly selects a bag of popcorn from the assembly line and it has a weight of 3.01 ounces. Then the worker randomly selects a bag of potato chips from the assembly line and it has a weight of 5.03 ounces. Which description closely matches the findings on the assembly line?

The popcorn bag assembly line is closer to the specifications given because its z-score is closer to the standard than the potato chip bag assembly line.

In a experiment, neither the participant nor those conducting the experiment know whether the participant will receive a placebo.

double-blind

Suppose you like to keep a jar of change on your desk. Currently, the jar contains the following: 18 Pennies 18 Dimes 16 Nickels 22 Quarters What is the probability that you reach into the jar and randomly grab a nickel and then, without replacement, a dime? Express your answer as a fraction or a decimal number rounded to four decimal places.

144 over 2701 or 0.0533

Determine whether an observational or experimental study is appropriate to address the following statement.: A car wash operator wants to find out if a need for additional staffing exists.

observational

Determine whether an observational or experimental study is appropriate to address the following statement.: A deli cart entrepreneur wants to identify the number of cars passing a billboard in a day.

observational

Determine whether the statement describes a population or a sample. The price of homes of all the professors at the local college.

population

Suppose that grade point averages of undergraduate students at one university have a bell-shaped distribution with a mean of 2.54 and a standard deviation of 0.44. Using the empirical rule, what percentage of the students have grade point averages that are greater than 3.42? Please do not round your answer.

2.5% How to solve: 3.42-2.54(over).44= 2 The empirical rule says that approximately 95% of data lies within 2 standard deviations of the mean. Because of the symmetry of the distribution, half of this 95% is above the mean and half is below. Thus, about 47.5% of the data is between the mean and 3.42. Also, since the bell-shaped distribution is symmetric, around 50% of the data is above the mean. Therefore, we can say that approximately 2.5% of the the students have grade point averages that are greater than 3.42.

Determine whether the statement describes a population or a sample.: The high school GPAs of all the employees at a textbook company.

population

The table below gives the list price and the number of bids received for five randomly selected items sold through online auctions. Using this data, consider the equation of the regression line,y^=b0+b1x, for predicting the number of bids an item will receive based on the list price. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Price in Dollars: 30 32 43 45 50 Number of Bids: 2 4 5 6 7 Step 2 of 6: Find the estimated y-intercept. Round your answer to three decimal places.

-3.656

The table below gives the list price and the number of bids received for five randomly selected items sold through online auctions. Using this data, consider the equation of the regression line,y^=b0+b1x, for predicting the number of bids an item will receive based on the list price. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Price in Dollars: 30 32 43 45 50 Number of Bids: 2 4 5 6 7 Step 1 of 6: Find the estimated slope. Round your answer to three decimal places.

0.211

The table below gives the list price and the number of bids received for five randomly selected items sold through online auctions. Using this data, consider the equation of the regression line,y^=b0+b1x, for predicting the number of bids an item will receive based on the list price. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Price in Dollars: 30 32 43 45 50 Number of Bids: 2 4 5 6 7 Step 3 of 6: Substitute the values you found in steps 1 and 2 into the equation for the regression line to find the estimated linear model. According to this model, if the value of the independent variable is increased by one unit, then find the change in the dependent variable y^.

0.211

The table below gives the list price and the number of bids received for five randomly selected items sold through online auctions. Using this data, consider the equation of the regression line,y^=b0+b1x, for predicting the number of bids an item will receive based on the list price. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant. Price in Dollars: 30 32 43 45 50 Number of Bids: 2 4 5 6 7 Step 6 of 6: Find the value of the coefficient of determination. Round your answer to three decimal places.

0.949