Stats AP Midterm

Dairy farmers are aware there is often a linear relationship between the age, in years, of a diary cow and the amount of milk produced, in gallons per week. The least-square regression line produced from a random sample is milk= 40.8-1.1(age). based on the model, what is the difference in predicted amounts of milk produced between a cow of 5 years and a cow of 10 years? a. A cow of five years is predicted to produce 5.5 fewer gallons per week b. A cow of five years is predicted to produce 5.5 more gallons per week c. A cow of five years is predicted to produce 1.1 fewer gallons per week d. A cow of five years is predicted to produce 1.1 gallons more each week e. A cow of five years in a cow of 10 years are both predicted to produce 40.8 gallons per week

A cow of 5 years is predicted to produce 5.5 more gallons per week

The buyers for an electronic store wants to estimate the proportion of defective wireless game controllers in a shipment of 5,000 controllers from the store's primary supplier. The shipment consists of 200 boxes each containing 25 controllers. The buyer numbers the boxes 1 to 200 and randomly selects six numbers in that range. she then opens the six boxes with the corresponding numbers, examines all 25 controllers in each of these boxes, and determines the proportion of the 150 controllers that are defective. What type of sample is this? a. biased random sample b. nonrandom sample c. simple random sample d. stratified random sample e. cluster random sample

Cluster random sample

If the owners beliefs are correct, which of the following statements must be true concerning event A and event B? a. Event a and B are mutually exclusive and are independent b. Event A and B are mutually exclusive and are not independent c. Event A and B are not mutually exclusive and are independent d. Event A and B are not mutually exclusive and are not independent e. Even a and B are not mutually exclusive and independence cannot be determined with the information given

Event A and Event B are not mutually exclusive and are independent

based on the dot-plots, which of the following is greater for the percent moisture of corn that for the percent moisture of soybeans? a. first quartile. b. the median. c. third quartile. d. range. e. IQR

The range

at a local ice cream store...Which of the following tables show the distribution of responses?

(Chart) Adults-50-20-70 children-100-40-140 total-150-60-210

based on the histogram, which of the following could be the interquartile range of the prices? a. 40. b. 21. c. 10. d. 5. e. 3

$5

for a random sample of 20 professional athletes, there is a strong, linear relationship between the number of hours they exercise per week and their resting heart rate. For the athletes in the sample, those who exercise more hours per week tend to have lower resting heart rates than those who exercise less. which of the following is a reasonable value for the correlation between the numbers of hours athletes exercise per week and their resting heart rate? a. .71. b. 0. c. -.14. d. -.87. e. -1

-0.87

In a certain school, 17 percent of the students are enrolled in a psychology course, 28 percent are enrolled in a foreign language course, and 32 percent are enrolled in either a psychology course or a foreign language or both. what is the probability that a student chosen at random from this school will be enrolled in both foreign language course and a psychology course? a. .05. b. .13. c. .20. d. .32. e. .45

0.13

The sale bin in a clothing store contains an assortment of t-shirts in different sizes. There are 9 small, 7 medium, and 4 large shirts. Alan is looking for a large shirt. He starts grabbing shirts one at a time and checking the size. After he checks each shirt, he leaves it outside the bin. What is the probability that the first large shirt he finds is the third one he checks? a. .004. b. .008. c. .120. d. .128. e. .140

0.140

at a small coffee shop, the distribution of the number of seconds it takes for a cashier to process an order is approximately normal with mean 276 seconds and standard deviation 38 seconds. which of the following is closest to the proportion of orders that are processed in less than 240 seconds? a. .17. b. .25. c. .36. d. .83. e. .95

0.17

Based on the meteorologist's estimates, approximately what is the probability that a future tropical storm will originate in the Pacific Ocean and be classified as major? a. .045. b. .125 c. .170. d. .400. e. .960

0.170

At a California college, 22% of students speak spanish, 5% speak French, and 3% speak both languages. What is the probability that a student chosen at random from the college speaks spanish but not French? a. .02. b. .17. c. .19. d. .20. e. .24

0.19

One student from the school will be selected at random. what is the probability that the student responded joy given that the selected student is in the age-group 6 to 8 years old? a. 89/332 b. 28/332. c. 28/106. d. 106/332. e. 28/89

28/106

For flights from a particular airport in January, there is a 30 percent chance of a flight being delayed because of icy weather. If a flight is delayed because of icy weather, there is a 10 percent chance the flight will also be delayed because of a mechanical problem. If a flight is not delayed because of icy weather, there is a 5 percent chance that it will be delayed because of a mechanical problem. If one flight is selected at random from the airport in January, what is the probability that the flight selected will have at least one of the two types of delays? a. .065. b. .335. c. .350. d. .450. e. .665

0.335

In a parking lot with 200 cars, 50 cars are white, 30 are red, and 20 cars are silver. one car will be selected at random from the parking lot. If each car in the parking has only one color, which of the following cannot be the probability that the selected car will be green? a. 0. b. .1. c. .2. d. .5. e. .6

0.6

opinion-polling organizations contact their respondents by sampling random telephone numbers. Assume that interviews can now reach about 71% of U.S households, while the percentage of those contacted who agree to cooperate with the survey is 31%. Each household, it can be safely assumed, is independent of the others. What is the probability of failing to contact a household or of contacting the household but not getting them to agree to the interview? a. .20. b. .50. c. .51. d. .78. e. .80

0.78

At a sporting event, cheerleaders will throw 50 bundled T-shirts into the crowd. The T-shirt sizes consist of 10 small, 15 medium and the remainder either large or extra large. suppose ana catches a T-shirt. What is the probablity that she will catch a T-shirt that is not a small size? a. .10 b. .20. c. .50 d. .67. e. .80

0.80

A police officer is using a radar device to check motorists' speeds. Prior to beginning the speed check, the officer estimates that 40 percent of motorists will be driving more than 5 miles per hour over the speed limit. Assuming that the police officer estimate is correct, what is the probability that among 4 randomly selected motorists, the officer will find at least 1 motorist driving more than 5 miles per hour over the speed limit? a. .0256. b. .1296. c. .3456. d. .8704. e. .9744

0.8704

A large store has a customer service department where customers can go to ask for help with store-related issue. According to store records, approximately 1/4 of all customers who go to the service department ask for helping finding an item. Assume the reason each customer goes to the service department is independent from customer to customer. Based on the approximation, which is the probability that at least 1 of the next 4 customers who go to the service department will ask for help finding an item? a. 4(1/4). b. 1-(1/4)^4. c. 1-(3/4)^4. d. 4(1/4)^1 (3/4)^4. e. (4/4) (3/4) (2/4) (1/4)

1-(3/4)^4

An exponential relationship exists between the explanatory variable and the response variable in a set of data. the common logarithm of each value of the response variable is taken, and the least sqaure regression line has an equation of log(y)=7.3-1.5x. which of the following is closest to the predicted value of the response variable for x=4.8? a. .1. b. .68. c. 1.105. d. 1.26. e. 14.5

1.26

The distrubution of monthly rent for one-bedroom apartments in a city is approximately normal with mean $936 and standard deviation $61. A graduate student is looking for a one-bedroom apartment and wants to pay no more than $800 in monthly rent. of the following, which is the best estimate of the percent of one-bedroom apartments in the city with a monthly rent of at most $800 a. 1.3% b. 2.5% c. 50% d. 95% e. 97.5%

1.3%

A friend of your plans to toss a fair coin 200 times. You watch the first 20 tosses and are suprised that she got 15 heads. But then you get bored and leave. How many heads do you expect her to have when she has finished all 200 tosses? a. 100. b. 105. c. 110. d. 115. e. 150

105

the caffeine content of 8-ounce cans of certain cola drink is approximately normally distributed with mean 33 milligrams. A randomly selected 8-ounce can containing 35 mg of caffeine is 1.2 standard deviations above the mean. Approximately what percent of 8-ounce cans of the cola have a caffeine greater than 35mg? a. 1%. b. 8%. c. 12%. d. 16%. e. 99%

12%

Ninety percent of the people who have a particular disease will have a positive result on a given diagnostic test. Ninety percent of the people who do not have the disease will have a negative result on this test. If 5 percent of a certain population has the disease, what percent of that population would test positive for his disease? a. 4.5%. b. 5%. c. 10%. d. 14%. e. 90%

14%

Shalise competed in a jigsaw puzzle competition where participants are timed on how long they take to complete puzzles of various sizes. Shalise completed a small puzzle in 75 minutes and a large jigsaw puzzle in 140 minutes. For all participants, the distribution of completion time for the small puzzle was approximately normal with mean 60 minutes and standard deviation 15 minutes. The distribution of completion time for the large puzzle was approximately normal with mean 180 minutes and standard deviation 40 minutes. Approximately what percent of the participants had finishing times greater than Shalise's for each puzzle? a. 16% on the small puzzle and 16% on the large puzzle b. 16% on the small puzzle and 84% on the large puzzle c. 32% on the small puzzle and 68% on the large puzzle d. 84% on the small puzzle and 84% on the large puzzle e. 84% on the small puzzle and 16% on a large puzzle

16% on the small puzzle and 84% on the large puzzle

At a certain store, the distribution of weights of cartons of large eggs is approximately normal with mean 26 ounces. based on the distribution, which of the following intervals will contain the greatest proportion of cartons of large eggs at the store? a. 20 to 24 oz. b. 22 to 26 oz. c. 24 to 28 oz. d. 26 to 30 oz. e. 28 to 32 oz

22 oz to 26 oz

the weight of adult male grizzly bears living in the wild in the continental unites states in approximately normally distributed with a mean of 500 pounds and a standard deviation of 50 pounds. the weight of adult female grizzly bears is approximately normally distributed with a mean of 300 pounds and a standard deviation of 40 pounds. approximately, what would be the weight of a female grizzly bear with the same standardized score (z-score) as a male grizzly bear with a weight of 530 pounds? a. 276 pounds b. 324 pounds c. 330 pounds. d. 340 pounds e. 530 pounds

324 pounds

The height of 3-year old boys is approximately normally distributed. Duncan and Shane are 3-year-old boys. Duncan is 32 inches tall and is at the 32nd percentile of the distribution. Shane is 34 inches tall and is at the 62nd percentile of the distribution. which of the following is closet to the mean of the highest distribution? a. 32.50 in b. 32.79 in c. 33 in. d. 33.21 in. e. 36.53 in

33.21

for a recent season in college football, the total number of rushing yards for that season is recorded for each running back. the mean number of rushing yards for the running backs that season is 790 yards. one running back had 1,637 rushing yards for the season, which is 2.42 standard deviations above the mean number of rushing yards. what is the standard deviation of the number of rushing yards for the running backs that season? a. 250 yard b. 300 yard. c. 350 yard. d. 400 yard e. 450 yard

350 yards

A fair coin has come up heads 10 times in a row. The probability that the coin will come up heads on the next flip is....?

50%

which of the following could be the median of the waiting times, in minutes? a. 2.5. b. 7.25. c. 12.25. d. 15. e. 17.5

7.25

The heights of adult women are approximately normally distributed about a mean of 65 inches, with a standard deviation of 2 inches. If Rachel is at the 95th percentile in height for adult women, then her height, in inches, is closest to a. 60. b. 62 c. 68. d. 70. e. 74

70

All surveyed 200 students at a school and recorded the eye color and the general of each student. Of the 80 male students who were surveyed, 60 had brown eyes. If eye color and gender are independent, how many female students surveyes would be expected to have brown eyes? a. 5. b. 20. c. 30. d. 90. e. 100

90

Measurements of water quality were taken from a river downstream from an abandoned chemical dumpsite. concentrations of a certain chemical were obtained from 9 measurements taken at the surface of the water, 9 measurements taken at mid-depth of the water, and 9 measurements taken at the bottom of the water. what type of study was conducted, and what is the response variable of the study? a. An experiment was conducted, and the response variable is the concentration of the chemical b. An experiment was conducted, and the response variable is the depth of water c. A census was conducted, and the response variable is the depth of water d. An observational study was conducted, and the response variable is the concentration of the chemical e. An observational study was conducted, and the response variable is the depth of water

An observational study was conducted, and the response variable is the concentration of the chemical

which of the following is the best description of a positive association between two variables? a. The values will create a line when graphed on the scatterplot b. The values will create a line with positive slope and graphed on a scatterplot c. As the value of one of the variables increases, the value of the other variable tends to decrease d. As the value of One of the variables increases, the value of the other variable tends to increase e. All values of both variables are positive

As the value of one of the variables increases, the value of the other variable tends to increase

A store owner reports that the probability that a customer who purchases a lawn mower will also purchase an extended warranty is 0.68. Which of the following is the best interpretation of the probability 0.68 ? a. For all customers who purchase a lawnmower 68% will also purchase extended warranty b. For all customers of the store 68% will purchase a lawnmower c. For all customers who purchase an extended warranty, 68% will use the warranty d. From the next 25 customers 17 will purchase an extended warranty e. From the next 25 customers 17 will purchase a lawnmower

For all customers who purchase a lawn mower, 68% will also purchase an extended warranty

A field.... Based on the scatterplots, for which gender does there appear to be evidence that the more time a lion cub spends playing, the sooner the cub is likely to begin hunting? a. For female cubs only b. For male cubs only c. For both male cubs and female cubs, with equal evidence d. For both male cubs and female cubs, with more evidence from female cubs than male cubs e. For neither male cubs nor female cubs

For female cubs only

Gina's doctor told her that the standardized score (z-score) for her systolic blood pressure, as compared to the blood pressure of other women her age is 1.50 . which of the following is the best interpretation of this standardized score? a. Gina's systolic blood pressure is 150 b. Gina systolic blood pressure is 1.50 standard deviations above the average systolic blood pressure of woman her age c. Gina systolic blood pressure is 1.50 above the average systolic blood pressure of woman her age d. Gina systolic blood pressure is 1.50 times the average systolic blood pressure for women her age e. Only 1.5% of women Gina's age have a higher systolic blood pressure than she does

Ginas systolic blood pressure is 1.50 standard deviations above the average systolic blood pressure of women her age.

which of the following does not describe a sampling method that has potential source of voluntary response bias for the administration of a survey about college athletics at a university? a. Giving the survey to 30 students selected at random from each of the eight dorms on campus b. Giving the survey to the first 50 students who call the University radio station after the broadcaster announces the survey on air c. Giving the survey to any student who stops at a table set up in the student union after the survey as advertised d. Giving the survey to all students who respond to an advertisement in the student newspaper e. Giving the survey to physical education majors who receive extra credit for completing the survey

Giving the survey to 30 students selected a random from each of the eight dorms on campus

in a certain school district, students from the grade 6 through grade 12 can participate in a school-sponsored community service activity. Which of the following is supported by the bar chart? a. The greatest number of participating students was in grade 9 b. A number of participating students in grade 6 was equal to the number of participating students in grade 7 c. The relative frequency of all participating students in grades six and seven was it combined .60 d. Grade 12 had the least relative frequency of participating students e. Grade 11 had the greatest relative frequency of participating students

Grade 12 had the least relative frequency of participating students

A local televison news station inculdes a viewer survey question about a current issue at the beginning of every evening news broadcast. Viewers are invited to use social media to respond to the question. the results of the survey are shared with the audience at the end of each broadcast. in relation to the opinions of the population of the region, which of the following is a possible reason why the results of such surveys could be biased? a. I only. b. II only. c. III only. d. II and III only. e. I, II, and III

I,II, and III

Which of the following statements about a least-squares regression analysis is true? a. I only. b. II only. c. III only. d. I and III only. e. I, II, and III

III only

After watching the show, each baby was presented with tray containing the helper puppet and the hinderer puppet, and the researchers recorded which puppet the baby reached for. The researchers wanted to determine whether the babies would reach for the helper puppet more than for the hinderer puppet? a. Flame in the lead might cause where on the Henderer puppet after 60 shows. The random assignment of color to roll permit more even wear between the helper and hinderer b. The puppeteer might grow tired of doing the same show with the same puppet colors. The random assignment of color to Roll keeps the shelf fresh for each performance c. If the same role is played by the same color puppet, the babies might show a preference for the color instead of the preference for the role d. The random assignment of color to role allows the researchers to determine if one color is better than another and teaching babies right from wrong e. Boys and girls might prefer different colors. The random assignment of color to roll ensures that the show is equally accessible to boys and girls

If the same role is played by the same color puppet, the babies might show a preference for the color instead of a preference for the role.

The probability that a randomly selected visitor to a certain website will be asked to participate in an online survey is .40. Avery claims that for the next 5 visitors to the site, 2 will be asked to participate in the survey. Is Avery interpreting the probability correctly? a. Yes, because two out of five is equal to 40% b. Yes, because participants in the survey are selected at random c. No, because there could be voluntary response bias d. No, because only 40% of all people visit the site e. No, because .40 represents probability in the long run over many visit to the site

No, because 0.40 represents probability in the long run over many visits to the site

for a specific species of fish in a pool, a wildlife biologist wants to build a regression equation to predict the weight of a fish based on its length. The biologist collects a random sample of this species of fish and finds that the lengths vary from .75 to 1.35 inches. The biologist uses the data from the sample to create a single linear regression model. would it be appropriate to use this model to predict the weight of a fish of this species that is 3 inches long? a. Yes because 3 inches falls above the maximum value of lengths in the sample b. Yes because the regression equation is based on a random sample c. Yes because the association between length and weight are positive d. No because 3 inches falls above the maximum value of lengths in the sample e. No because there may not be any 3 inch fish of the species in the pond

No, because 3 inches falls above the maximum value of lengths in the sample

A high school science teacher has 78 students. Of those students, 35 are in the band and 32 are on a sports team. There are 16 students who are not in the band or on a sports team. One student from the 78 students will be selected at random. Let event B represent the event of selecting a student in the band, and let event 5 represent the event of selecting a student on a sports team. Are B and S mutually exclusive events? a. No, because 5/78 b. No, because 48/78 c. No, because 62/78 d. Yes, because 5/78 e. Yes, because 62/78

No, because P(B-S)=5/78

a researcher collected data on the age, in years, and the growth of sea turtles. the following graph is a residual plot of the regression of growth versus age. Does the residual plot support the appropiateness of a linear model? a. Yes, because there is a clear pattern displayed in the residual plot b. Yes, because about half of the residuals are positive and half are negative c. Yes, because as age increases the residuals increase d. No, because the points appear to be randomly distributed e. No, because the graph displays a U-shaped pattern

No, because the graph displays a U-shaped patterns

roger claims that the two statistics most likely to change greatly when an outlier is added to a small data set are the mean and the median. Is rogers claim correct? a. Yes, both the mean and median are likely to change greatly b. No, only the mean is likely to change greatly c. No, only the median is likely to change greatly d. No, neither the mean or nor median are likely to change greatly e. There's not enough information to determine if the mean or median is likely to change greatly

No, only the mean is likely to change greatly

Events D and E are independent, with P(D)=.6 and P(D and E)=.18. Which of the following is true? a. P(E)=.12. b. P(E) = .40. c. P(D or E)=.28c. d. P(D or E)=.72. e. P(D or E)=.90

P(D or E)=.72

which of the following is the correct order from least to greatest for the values of r, s, and t? a. rst. b. rts c. str. d. trs. e. tsr.

R, T, S

Which of the following is the best reason for the random assignment of a treatment level to an experimental unit? a. Randomization tend to minimize the effects of uncontrolled variables such as water temperatures, so that such factors are not confounded with the treatment effects b. Randomization will make up for improper experimental design data collection and analysis c. Randomization makes the analysis easier since the data can be entered into the computer in any order d. Randomization is required by statistical consultants before they will analyze the experiment e. Randomization means that the experiment would not need to be replicated

Randomization tends to minimize the effects of uncontrolled variables, such as water temperature, so that such factors are not confounded with the treatment effects

The table shows data that were collected from people who attended a certain high school basketball game and indicates the team each person rooted for and whether each of these people purchased food during the game. A person who attended the game will be selected at random. Which of the following correctly interprets mutually exclusive events represented by the table? a. Rooting for the home team and rooting for the away team b. Rooting for the home team in purchasing food during the game c. Rooting for the away team and purchasing food during the game d. Rooting for the home team and not purchasing food during the game e. Not reading for the home team and not purchasing food during in the game

Rooting for the home team and rooting for the away team

At a large airport, data were recorded for one month on how many baggage items were unloaded from each flight upon arrival as well as the time required to deliver all the baggage items on the flight to the baggage claim area. A scatterplot of the two variables indicated a strong positive linear association between the variables. which of the following statements is a correct interpretation of the world "strong" in the description of the association? a. A least squares model predicts that the more baggage items that are unloaded from a flight, the greater the time required to deliver the items to the baggage claim area b. The actual time required to deliver all the items to the baggage claim area based on the number of items on the road it will be very close to the time predicted by a least squares model c. The time required to deliver an item to the baggage claim area is relatively constant, regardless of the number of baggage items unloaded from a flight d. The variability in the time required to deliver all items to the baggage claim area is about the same for all flights, regardless of the number of items unloaded from the flight e. The time required to unload baggage items from a flight is related to the time required to deliver the items to the baggage claim area

The actual time required to deliver all the items to the baggage claim area based on the number of items unloaded will be very close to the time predicted by a least-squares model

based on the histogram, which of the following correctly compares the two distributions? a. The median of the earthquake disturbances is equal to the median of the mining disturbances b. The median of the earthquake disturbances is less than the median of the mining disturbances c. The range of the earthquake disturbances is equal to the range of the mining disturbances d. The range of the earthquake disturbances is less than the range of the mining disturbances e. The mode of the earthquake disturbances is equal to the mode of the main disturbances

The median of the earthquake disturbances is less than the median of the mining disturbances

As part of a study on facility needs, the administrators of a university wanted to estimate the percent of students who use the exercise facilities on a regular basis. From the 34,000 students who attend the university, a random sample of 370 male students and 400 female students was selected. Of the 770 students selected, 493 students indicated that they use the exercise facilities on a regular basis. What are the population and the sample of the study? a. The population is the 770 students who were selected in a sample is 493 students who indicated that they use the exercise facilities on a regular basis b. The population is the 770 students who were selected in the samples whether each student in the survey uses the exercise facility on a regular basis c. The population is the 34,000 students who attend the university and the sample is whether each student in the survey is male or female d. The population is the 34,000 students who attend the university in the sample 770 students who are selected e. The population is 34,000 students who attend the university and the sample is the 493 students who indicated that they use the exercise facilities on a regular basis

The population is the 34,000 students who attend the university, and the sample is the 770 students who were selected

As part of a science experiment, a student recorded 10 measurements of the temperature of a liquid. one of the measurements was an outlier compared with the other 9 measurements. which of the following must be true about the 9 measurements, excluding the outlier, when compared with the 10 measurements? a. The median of the nine measurement is less than the median of the 10 measurements b. The median of the nine measurements is greater than the median of the 10 measurement c. The maximum of the nine measurements is less than the maximum of the 10 measurements d. The maximum of the nine measurements is greater than the maximum of the 10 measurements e. The standard deviation of nine measurements is less than the standard deviation of the 10 measurements

The standard deviation of the 9 measurements is less than the standard deviation of the 10 measurements

at a college the scores on the chemistry final exam are approximately normally distributed, with a mean of 75 and a standard deviation of 12. the scores on the calculus final are also approximately normally distributed, with a mean of 80 and a standard deviation of 8. A subject scored 81 on the chemistry final and 84 on the calculus final. Relative to the students in each respective class, in which subject did this student do better? a. The student did better in chem b. The student did better in Calc c. The student did equally well in each course d. There is no basis for comparison, since the subjects are different from each other and are in different departments e. There is not enough information for comparison, because the number of students in each class is not now

The student did equally well in each course

Eighteen individuals who use a particular form of social media were assigned a new user interface to use when logging in to their accounts. After using the new user interface for a week, each individual was asked to rate how easy or hard the new user interface was to use on a scale from 1 (extremely easy) to 9 (extremely hard). Which of the following correctly identifies why this is not a well designed experiment? a. There was a lack of control because not all individuals in the study used login passwords of the same length b. The individuals may not have been randomly selected c. There was not enough replication because the individuals used the new user interface for only one week d. There was a lack of control because not all individuals in the studies use social media e. The study was not comparative Dash only one treatment was used

The study was not comparative-only one treatment was used.

if the interval size is decreased from $200 to $100, which of the following must remain the same on the new histogram? a. heights of bars. b. widths of bars. c. number of bars. d. sum of frequencies. e. shape of distribution

The sum of the frequencies

A new restaurant....From the 10 indentical cuts of lamb, 2 are randomly selected to roast using each of the time-temperature combinations in the same oven. The quality of the finished product is evaluated for each roast. which of the following is true? a. Explanatory variable is the quality of the finished lamb b. The response variable is the roasting temperature for the lamb c. If the experiment is repeated identical results will be expected d. There should be a control group e. The two cuts that are being roasted for each time temperature combination or an example of replication

The two cuts that are being roasted for each time-temperature combination are an example of replication

A recent study examined 699 car accidents in Toronto over a fourteen-month period. Records of phone-service providers were used to determine whether the driver was using a cell phone during or immediately before the accident. Overall, the researchers found that drivers using cell phones were 4.3 times as likely to have an accident as drivers who were not using cell phones. the results was statistically significant. which of the following can be concluded from this study? a. Cell phone use increases the likelihood of a car accident b. There is an association between cell phone used in car accidents but not necessarily a casually relationship c. There is a correlation between cell phone usage and accident but not necessarily an association d. Association between cell phone use an accident is negative e. Cell phone used causes more accidents in Canada but not necessarily in the United States

There is an association between cell phone use and accidents, but not necessarily a causal relationship

A tennis ball was thrown in the air. The height of the ball from the ground was recorded every millisecond from the time the ball was thrown until it reached the height from which it was thrown. The correlation between the time and height was computed to be 0. What does this correlation suggest about the relationship between the time and height. a. There's no relationship between time in height b. There is no linear relationship between time and height c. The distance the ball traveled upward is the same as the distance traveled downward d. The correlation suggest that there is measurement or calculation error e. The correlation suggest that more measurement should be taken to better understand the relationship

There is no linear relationship between time and height

A regional transportation authority is interested in estimating the mean number of minutes working adults in the region spend commuting to work on a typical day. A random sample of working adults will be selected from each of three strata: urban, suburban, and rural. Selected individuals will be asked the number of minutes they spend commuting to work on a typical day. Why is stratification used in this situation? a. To remove bias when estimating the proportion of working adults and living urban suburban and rural areas b. To remove bias when estimating the mean commuting time c. To reduce bias when estimating the mean commuting time d. To decrease variability in estimate of the proportion of working adults and living urban suburban and rural areas e. To decrease the variability in estimates of the mean commuting time

To decrease the variability in estimates of the mean commuting time

Suppose a roadrunner has a total length of 59.0 cm and tail length of 31.1 cm. Based on the residual, does the regression model overestimate or underestimate the tail length of the roadrunner? a. underestimate because pos residual b. underestimate because neg residual c. overestimate because pos residual d. overestimate because neg residual e. neither because 0 residual

Underestimate, because the residual is positive.

Janelle collected data on the amount of time in minutes each person in a large sample of customers spent in a local store. The data also included recorded the gender of each costumer. these data were used to generate the box-plots shown. Which of the following statements is true? a. The range in the amount of time in minutes males in the sample of customers spent in the store is approximately 40 minutes b. The mean amount of time in minutes males in the sample of customers spent in the store is approximately 20 minutes c. The third quartile of the amount of time and minutes males in the sample of customers spent in the store is approximately 45 minutes d. The IQR range of the amount of time in minutes females in the sample of customers spent in the store is 15 minutes e. Approximately half of the males in the sample of customers spent at least as much time in the store as any female of customers

approximately half of the males in the sample of customers spent at least as much time in the stores as any female in the sample customers

A scatterplot of student heights, in inches, versus corresponding arm span length, in inches, is shown below. One of the points in the graph is labeled A. If the point labeled A is removed, which of the following statements would be true? a. The slope of the least squares regression line is unchanged and the correlation coefficient increases b. The slope of the least squares regression line is unchanged and the correlation coefficient decreases c. The slope of the least squares regression line increases and the correlation coefficient increases d. The slope of the least squares regression line increases in the correlation coefficient decreases e. Slope of the least squares regression line decreases in the correlation coefficient increases

the slope of the least squares regression line increases and the correlation coefficient increases

List the sample spaces and tell whether the outcomes are equally likely. A family has two children; record the number of girls. a. Zero, one equally likely b. One, two equally likely c. One, two not equally likely d. Zero, one, two equally likely e. Zero, one, two not equally likely

{0,1,2}, not equally likely

List the sample space and tell whether the outcomes are equally likely. A family has two children; record the genders in order of birth. a. BB, BG, GB, GG not equally likely b. BB, BG, GB, GG equally likely c. B, G equally likely d. BB, BG, GG, not equally likely e. BB, BG, GG equally likely

{BB,BG,GB,GG} equally likely