APs statistics semester final

. The distribution 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 the following, which is the best estimate of the percent of one-bedroom apartments in the city with a monthly renit of most 800?

1.3%

12. A friend of your plans to toss a fair coin 200 times . You watch the first 20 tosses and are surprised 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 ?

105

The caffeine content of 8-ounce cans of a certain cola is approximately normally distributed with mean 33 milligrams (mg). 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 content greater than mg ?

12%

4. 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 percent of a certain population has the disease, what percent of that population would test positive for the disease?

14%

2. A large store has a customer service department where customers can go to ask for help with store-related issues. According to store records, approximately all customers who go to the service department ask for help finding an itemAssume the reason each customer goes to the service department is independent from customer to customer. Based on the approximation , what 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?

1- (3/4)^4

9. A new restaurant is interested in determining the best time-temperature combiration for roasting a fivepound cut of lamb. The times to be tested are 45 minutes, 60 minutes, and 90 minutes at temperatures of 350 degrees Fahrenheit and degrees Fahrenheit for each time, with the exception of the 90minute - 425 degree combination. That combination is being eliminated because it will overcook the lamb, which leaves five combinations remainingFrom 10 identical cuts of lamb, 2 are randomly selected to roast using cach 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 ?

The two cuts are being roasted for each time temperature combination or examples of replication

Instagram summarizes the response of 100 people when I asked what is the price of the last meal you purchased

$5

For a random sample of 20 professional athieten, there is relationship between the of they exercise week and their resting heart rate for the athletes in the sample, those who Exercise more hours per week tend to have lower heart rate than those who exercise less Which of the following is for the correlation between number of hours per and ?

-0.87

List the sample space and tell whether the outcome is likely a family has two children record the number of girls

0,1,2 are not equally likely

Measurements of water quality were taken from a river downstream from an abandoned chemical dumpsite. Concentrations of certain chemical were obtained from measurements taken at the surface of the water, 9 measurements taken at mid-depth of the water, and measurements taken at the bottom of the water, type of study was conducted, and what is the response variable the study

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

9. At a local ice-cream store, 210 people were surveyed on whether they preferred eating ice cream from a cone or a cup. Of the 210 people surveyed, 70 were adults and 140 were children. Of the responses, 150 indicated the cone as the preferred method of eating ice cream. For those surveyed, there was no association between age and preferred method of eating ice cream. Which of the following tables shows the distribution of responses?

C

Which of the following is the best description of a positive association between two variables

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

4. A local television news station includes a viewer survey question about a current issue at the beginning of every evening news 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? 1. Viewers with strong opinions about the current issue are more likely to response than are viewers without strong opinions. II. The opinions of viewers of one television station are not necessarily representative of the population of a region. . Viewers with access to social media are not necessarily representative of the population of a region.

I II and III

Which of the following statements about loust squares regression analysis is true A with a large residual is an outlier A point with high leverage has a y value that not consistent with the other in the III The removal of influential point from a data set could change the of coefficient

III only

Event D & E are independent if P(D and E) = 0.18 which of the following is true

P(D or E) = 0.72

In a large set of data that is approximately normally distributed R is the value in the data set that has a Z score of negative 1 s is the value of the first quartile andT is the value of the 20th percentile

R,t,s

-6. In a parking lot with 200 cars, 50 cars are white30 cars are red, and 20 cars are silver. One car will be selected at random from the parking . If each car in the parking has only one color, which of the following cannot be the probability that the selected car will b green ?

0.6

11. Opinion-polling organizations contact their respondents by sampling random telephone numbers. Assume now reach about 71% of U.S. households, while the percentage of those contacted who agree to cooperate with the survey 31% Each householdit can be safely assumed, is independent of the others. What is the probability of failing to contacting the household but not getting them to agree to the interview?

0.78

7. A police officer is using a radar device to check motorists' speeds. Prior to beginning the speed checkthe 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's estimate is correct, what is the probability that among 4 randomly selected motorists, the officer will find at least motorist driving more than 5 miles per hour over the speed limit?

0.8704

11. Students at a local elementary school were shown a painting and asked which emotion - , happiness , love, anger -they felt by looking at the painting . The students were classified by their age . The following table summarizes the responses of the students by age -group .

28/106

A fair coin has come up heads 10 times in a row the probability that the coin will come up head on the next one is

50%

Disregard below is the frequency of waiting time in minutes for 175 patients in a dentist office which of the following could be the median of the waiting times in minute

7.25

The height of an adult women are approximately normally distributed about a mean of 65 inches with a standard deviation of 2 inches of Rachel is in the 99th percentile in height for adult women than her height in inches is closest to?

70

1. All surveyed 200 students at a school and recorded the eye color and the gender 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 surveyed would be expected to have brown eyes?

90

4. Dairy farmers are aware there is often a linear relationship between the age, in years, of a dairy cow and the amount of milk produced, in gallons per week. The least-squares 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 cow of 5 years is predicted to produce 5.5 gallons per week

Janelle collected data on the amount of times in minutes each person In a large sample of customers spent an A local store the data also includes the gender of each customer which of the following statements is

Approximately half of the males in the sample of customer spend at least as much time in the store as females in the sample of customers

for an electronics store wants to the proportion of defective wireless controller in a shipment of controllers from the store's primary supplier. The shipment consists of 200 boxes each containing 25.controllersThe buyer the boxes from 1 to 200 and randomly selects six numbers in that range. She then opens the six boxes with the corresponding numbers, examines all controllers in each of these boxes, and determines the proportion of the 150 controllers that are defective What type of sample is this?

Cluster random sample

1. 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, 10 . Which of the following is the best interpretation of this standardized score?

Gina's systolic blood pressure is 1.50 standard deviation above the average systolic blood pressure of women her age

Which of the following does not describe a survey method that has a potential source of voluntary response bias for the administration of a survey about college athletics at a university

Giving that the survey has 30 students selected at random from the eight dorms on campus

7. As part science experiment, a student recorded to measurements of the temperature of a liquidOne 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 measurements (NoteAn number that is greater than the upper quartile or less than the lower quartile by at least 1.5 times the interquartile range

Is there a deviation of nine measurements version of 10 measurements

The probability that a randomly selected visitor to a certain website will be asked to participate in an online survey is 0.40 Avery claims that for the next visitors to the site 2 will be asked to participate in the surveyAvery interpreting the probability correctly?

No because .40% represents probability in the Long run over many visits to sites

10. For a specific species of fish in a pond, 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?

No because 3 inches falls above the maximum value for the length in the sample

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 the baggage the flight the baggage claim . A scatterplot of the two variables indicated a strongpositive linear association between the variables. Which of the following statements is correct interpretation of the word "strong in the description of the association ?

The actual time required to deliver all the items to the baggage claim area based on the number of items and loaded will be very close to the time predicted by least square regression model

One way to measure the duration of a subterranean disturbance such as earthquakes And mine is to calculate the route meantime the following histogram some reason distribution of the room meantime for two sources of the disturbance

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

10. 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 basisWhat are the population and the sample of the study?

The population is 34,000 students who attend university in the sample is 770 students who are selected

Green moisture is a characteristic of grains that affect the price paid for grading a sample of 38 loads of corn evaluate it for moisture as percentage of the total weight a different sample of 28 loads of soybeans was also valuated for moisture based on the dot plot which of the following is greater for percentage of moisture of corn the percentage of moisture for soybeans

The range

Define histogram summarizes the amount spent on a plane ticket to travel home in dollars for a group of 30 college student the interval size Is decreased from 200 to 100 which of the following must remain the same on a new histogram

The shape of the distribution

5. A scatterplot of student heights, inches, versus corresponding arm span length, in inches, is shown below. One of the points in the graph is labeled A. 74 If the point labeled A is removed, which of the following statements would be true?

The slope of the least squared regression line increases and the correlation coefficient increases

A roadrunner is a desert bird that tends to run instead of While running, the roadrunner its tail as a balance. A sample of 10 roadrunners was taken, and the birds total length, in centimeters (em), and tail length, in were recorded . The output shown in the table is from a least -squares regression to predict tail length given total length . Supposed to run brother has a total length of 59 cm and a tail length of 31 cm based on the residual does the regression model overestimate or underestimate the telling of the roadrunner

Underestimate because The residual is positive

List the sample space and tell whether the outcomes are equally likely a family has two children record the genders in order of birth

bb bg gb gg are equally likely

And I started school district students in grades six through 12 participate in school sponsored community service activity the following bar chart shows the relative frequencies of students from each grade who participate in community service activity which of the following is supported by the bar chart

grade 12 Had the least relative frequency of participating students

. A recent study examined 699 car accidents in Toronto over a fourteen-month period. Records of phone-service providers were 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 result was statistically significant. Which of the following can be concluded from this study

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

6. A tropical storm is classified as major if it has sustained winds greater than 110 miles per hour. Based on data from the past two decades, a meteorologist estimated the following percentages about future storms. 20% of all tropical storms will originate in the Atlantic Ocean, of which 20% will be classified as major. 30% of all tropical storms will originate in the eastern Pacific Ocean, of which 15% will be classified as major. 50% of all tropical storms will originate in the western Pacific Ocean, of which 25% will be classified as major.

0.170

Allie California college 22% of students speak Spanish 5% speak French and 30% speak both languages what is the probability that a student chosen at random from the college speak Spanish but not French

0.19

2. 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 delayed because of weather, there is a 10 percent chance the flight will also be delayed because of a mechanical problemIf 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?

0.335

9. The SC Electric Company has bid on two electrical wiring jobs. The owner of the company belleves that the probability of being awarded the first job (event A) is 0.75; the probability of being awarded the second job (event B) is 0.5; and the probability of being awarded both jobs (event (A and B)) is 0.375. If the owner's beliefs are correct, which of the following statements must be true concerning event A and event B?

Event a and event be or not mutually exclusive and are independent

4. 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

For all customers who purchase the lawn more 68% will also purchase an extended warranty

1. A field researcher who studies lions conjectured that the more time a cub spends playing, the the cub will begin to bunt Observational data were collected from 20 Jion cubs. The researcher recorded how they spent playing and the age when they began hunting. Because male and female lions have different hunting behaviors, the researcher recorded the data for males and females separately . The two scatterplots show the data for the 10 female lions and the 10 male lions.

For female cubs only

3. In a certain school, 17 percent of the students are enrolled in a psychology course, 28 percent are enrolled in a foreig 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 a foreign language course and a psychology course ?

0.13

10. The sale bin a clothing store contains an assortment of t-shirts 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 shirt he finds is the third he checks?

0.140

At a small coffee shop, the distribution of the number of seconds takes for cashier process an order is approximately normal wh 276 seconds and standard deviation 38 seconds Which of the following is closest the proportion or orders that are processed in less than 240 seconds

0.17

An exponential relationship exist between the explanatory variable and a response variable in a set of data a common logarithm of each value of the response variable is taken in Alys Krab aggression line has the equation log (y)= 7.3 - 1.5. Which of the following is closest to the predicted value of response variables for x= 4.8

1.26

11. 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 minutesThe distribution of completion time for the large puzzie was approximately normal with mean 180 minutes and standard deviation 40 minutes

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

At a certain store the distribution of weights of cartons of 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

28oz to 32oz

6. The weight of adult male grizzly bears living in the wild in the continental United States is 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?

324 pounds

The height of 3-year-old boys is approximately normally distributed. Durican and Shane are 3-year-old boys is 32.0 inches is at the 32nd percentile of the distribution Shane is 34.0 inches tall and is at the 2nd percentile of the distributionWhich of the following is closest to the mean of the height distribution?

33.21 inches

8. 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 ?

350

As part of the show, a green puppet and a yellow puppet served as the helper and hinderer. For each baby, a coin was tossed to determine which color would serve which role. Which of the following is the most important reason for the random assignment of color to role in the study?

If the same role is played by the same color pop of the babies might show a preference in color instead of the role

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, ench 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 well designed experiment

The study not comparative only one treatment was use

8. A high school science teacher has 78 students. Of those students, are in the band and on a sports team There are 16 students who are not in the band or on a sports teamOne student from the 78 students will be selected randomevent represent the event of selecting a student in the band, and let event represent the event of selecting a student on a sports team. Are B and S mutually exclusive events?

No because P (B ^ S) = 5/78

A college research or collect the data on the age year and years and the growth of see turtles the following graph is residual plot of the regression of growth versus age does the residual plot support the appropriateness of a linear model

No because the graph displays a U pattern

Researchers are investigating the effect of pH level in water on the breeding habits of the moon jellyfish . As part of laboratory experiment, they will randomly assign one of three treatments, low pH , medium pH, or high pH, to the water in the tanks that hold the jellyfish . Which of the following is the best reason for the random assignment of a treatment level to an experimental units

Randomization tends to minimize the effects of uncontrollable variables such as water temperatures so that such factors are not confounded with the treatment effects

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 student 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 ?

The student did equally well in each course

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 thrown until it reached the height from which it was thrown. The correlation between the time and height was computed to be What does this correlation suggest about the relationship between the time and height?

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

To decrease the number of variability in estimates of the mean commuting time

Roger claims that to statistics most likely to change greatly when an outlier is added to a small data set is the mean and the median is Rogers claim is correct

no only the mean is likely to change greatly

1. The table shows data that were collected from people who attended a certain high school basketball game and indicates the team cach person rooted for and whether each of these people purchased food during the game. A person who attended the game will be selected at randomWhich of the following correctly interprets mutually exclusive events represented by the table?

rooting for the home team and rooting for the away team