A zoologist studying adult bears measures a number of different variables. One variable is the body temperature of the bear during hibernation. Which of the following is the best description of the distribution of this variable.

A review of voter registration records in a small town yielded this table of the number of males and females registered as Democrat, Republican, or some other party affiliation. Which of the following bar graphs represents the distribution of party affiliation among all voters in this town?

Above is a graphical presentation of information from the World Bank about the percentage of land in four East African countries that is forest. What’s wrong with this method of presenting information?

Above is a dot plot of voter turnout (as a percentage of voting-age population) for the 50 states—plus the District of Columbia—in a recent presidential election. Which of the following best describes this distribution?

The stem-and-leaf diagram gives the distribution of the ages in years of 20 participants at a family reunion. Which of the following statements about the distribution is correct?

Independently selected groups of middle-school children were given a poem to memorize. After a certain period of time, they were asked to recall as much of the poem as they could. A back-to-back stem plot of the distribution of the number of words that each group of children could correctly remember is displayed. Which of the following statements about these data is true?

The box plots show the distribution of test scores in Ms. Williams’s two sections of calculus. Based on these box plots, which one of the following statements must be true?

Given is a dot plot of voter turnout (as a percentage of voting-age population) for the 50 states—plus the District of Columbia—in a recent presidential election. Approximately what percentage had a turnout above 65%?

The owner of a convenience store keeps track of how many customer buy lunch food during the “noon rush” each day for four days and calculates that the mean number of customers for those four days is 52. How many customers must come in on the fifth day to make the five-day mean 54?

Which of the distributions displayed in the dot plots has the highest standard deviation?

According to the 1.5 x IQR rule, how many outliers are there in the data set 72, 110, 114, 115, 118, 123, 144, 156?

The histogram shows the typical travel time to school (self-reported) for 50 high school students. Which of the following statements is true about the mean and median of this distribution?

Jerome’s summer reading list has 8 books, and he is examining the number of pages in each book. After calculating the mean, median, standard deviation, and interquartile range, he realized that the longest book is actually 100 pages longer than he thought it was. Which of his measurements does he need to recalculate?

You record the weight, age, and eye color of a sample of 1560 men at a company. The number and type of variables you have recorded is

The principal at an elementary school wanted to do research on which type of pet would be best for the first grade class. She took a sample of 54 first graders and asked which pet they had in their home. The results are displayed in the graph. Which of the following are true about the graph?

Which of the following bar charts matches the data represented in the pie chart above?

Temperatures are being measured regularly to fight the spread of COVID 19. A temperature above 100.1F is considered a fever and will be denoted with H. A list of 9 temperatures is shown.

H 99.1 H 98.1 H 98.9 97.9 96.5 97.1

The median temperature of the sample is

Researchers record the weights in pounds of 40 cheetahs in the wild. The histogram shows the data that were collected.

The percentage of cheetahs that weigh more than 200 lbs is closest to

Researchers record the weights in pounds of 40 cheetahs in the wild. The histogram shows the data that were collected.

Which of the following statements about the distribution is NOT correct?

The first quartile of the score distribution is equal to

The mean age of female teachers is 36, the mean age of male teachers is 33. What must be true about the mean age of all teachers?

What percent of all large companies receiving surveys responded?

Which of the following conclusions is not supported by the data? (select all that apply)

The cumulative relative frequency graph describes the distribution of weights (in grams) of tomatoes grown in a laboratory experiment. Which of the following weights is closest to the median of the distribution?

For the density curve shown, which of the following statements is true?

An office uses two brands of fluorescent light bulbs in its overhead light fixtures. From past experience, it is known that Brand A bulbs have a mean life length of 3000 hours and a standard deviation of 200 hours, while Brand B bulbs have a mean life length of 2700 hours and a standard deviation of 250 hours. Which bulb has a longer life relative to all bulbs of its brand, a Brand A bulb that lasts 3150 hours or a Brand B bulb that lasts 2850 hours?

Javier’s school bus is always late. Below are data on how many minutes late the bus was for 15 days in February. What is the 60th percentile of this distribution? *

1 2 2 2 3 3 4 4 4 5 6 7 8 10 12

The weights of cockroaches living in a university dormitory follow a Normal distribution with mean 80 grams and standard deviation 5 grams. The percentage of cockroaches having weights between 72 grams and 88 grams must be

Scores on the American College Testing (ACT) college entrance exam follow a Normal distribution with mean 18 and standard deviation 6. Lisa’s standardized score on the ACT was z = -0.7. What was her actual ACT score?

What is the 25th percentile of the standard Normal distribution?

The lifetime of a 2-volt battery in constant use has a Normal distribution with a mean of 516 hours and a standard deviation of 20 hours. The proportion of batteries with lifetimes that exceed 520 hours is approximately

The lifetime of a 9-volt battery in constant use has an approximately Normal distribution with a mean of 516 hours and a standard deviation of 20 hours. Which of the following is the approximate lifetime of a battery that lasts longer than 90% of all batteries?

The lifetime of 9-volt battery in constant use has an approximately Normal distribution with a mean of 516 hours and a standard deviation of 20 hours. Which of the following best describes the distribution of standard scores for the lifetimes of such batteries?

Fuji apples grown at a certain orchard have a mean weight of 5.2 ounces with a standard deviation of 0.8 ounces. Suppose the scale the orchard owner uses systematically underweighs apples by 0.2 ounces and also weighs the apples in grams, rather than ounces. What would the mean and standard deviation of these apples’ weights be as determined by this scale? (Note: 1 ounce ≈ 28 grams).

Which interval shows 99.7% of the data given a mean of 15 and a standard deviation of 3?

What percent of people within 3 standard deviations of the mean?

What percent of people within 2 standard deviations of the mean?

What percent of people within 1 standard deviation of the mean?

A school guidance counselor examines how many extracurricular activities students participate in and their grade point average. The guidance counselor says, “The evidence indicates that the correlation between the number of extracurricular activities a student participates in and his or her grade point average is close to 0.” Which of the following is the most appropriate conclusion?

An AP®® Statistics student designs an experiment to see whether today’s high school students are becoming too calculator-dependent. She prepares two quizzes, both of which contain 40 questions that are best done using paper-and-pencil methods. A random sample of 30 students participates in the experiment. Each student takes both quizzes—one with a calculator and one without—in a random order. To analyze the data, the student constructs a scatterplot that displays a linear association between the number of correct answers with and without a calculator for the 30 students. A least-squares regression yields the equation𝐶𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑜𝑟ˆ=−1.2+0.865(𝑃𝑒𝑛𝑐𝑖𝑙)Calculator^=−1.2+0.865(Pencil) 𝑟=0.79.

Scientists examined the activity level of 7 fish at different temperatures. Fish activity was rated on a scale of 0 (no activity) to 100 (maximal activity). The temperature was measured in degrees Celsius. A computer regression printout and a residual plot are provided. Notice that the horizontal axis on the residual plot is labeled “Fitted value,” which means the same thing as “predicted value.” What is the correlation between temperature and fish activity?

Scientists examined the activity level of 7 fish at different temperatures. Fish activity was rated on a scale of 0 (no activity) to 100 (maximal activity). The temperature was measured in degrees Celsius. A computer regression printout and a residual plot are provided. Notice that the horizontal axis on the residual plot is labeled “Fitted value,” which means the same thing as “predicted value.” What was the actual activity level rating for the fish at a temperature of 20°C?

Scientists examined the activity level of 7 fish at different temperatures. Fish activity was rated on a scale of 0 (no activity) to 100 (maximal activity). The temperature was measured in degrees Celsius. A computer regression printout and a residual plot are provided. Notice that the horizontal axis on the residual plot is labeled “Fitted value,” which means the same thing as “predicted value.”Which of the following gives a correct interpretation of 𝑠s in this setting?

Which of the following statements is not true of the correlation 𝑟 between the lengths (in inches) and weights (in pounds) of a sample of brook trout?

When we standardize the values of a variable, the distribution of standardized values has mean 0 and standard deviation 1. Suppose we measure two variables 𝑋 and 𝑌 on each of several subjects. We standardize both variables and then compute the least-squares regression line. Suppose the slope of the least-squares regression line is –0.44.

There is a linear relationship between the number of chirps made by the striped ground cricket and the air temperature. A least-squares fit of some data collected by a biologist gives the model 𝑦̂ =25.2+3.3𝑥, where 𝑥 is the number of chirps per minute and 𝑦̂ is the estimated temperature in degrees Fahrenheit. What is the predicted increase in temperature for an increase of 5 chirps per minute?

The scatterplot shows the relationship between the number of people per television set and the number of people per physician for 40 countries, along with the least-squares regression line. In Ethiopia, there were 503 people per TV and 36,660 people per doctor. Which of the following is correct?

The first scatterplot shows the lean body mass and metabolic rate for a sample of 5 adults. For each person, the lean body mass is the subject’s total weight in kilograms less any weight due to fat. The metabolic rate is the number of calories burned in a 24-hour period. Because a person with no lean body mass should burn no calories, it makes sense to model the relationship with a direct variation function in the form 𝑦=𝑘𝑥. Models were tried using different values of 𝑘(𝑘=25,𝑘=26), and the sum of squared residuals (SSR) was calculated for each value of 𝑘. Given is a second scatterplot, this one showing the relationship between SSR and 𝑘: According to the scatterplot, what is the ideal value of 𝑘 to use for predicting metabolic rate?

We record data on the population of a particular country from 1960 to 2010. A scatterplot reveals a clear curved relationship between population and year. However, a different scatterplot reveals a strong linear relationship between the logarithm (base 10) of the population and the year. The least-squares regression line for the transformed data is log(population)ˆ=−13.5+0.01(year).

Based on this equation, which of the following is the best estimate for the population of the country in the year 2020?

a controlled study in which the researcher attempts to understand cause-and-effect relationships by assigning subjects to groups and deciding which treatments each group receives

A large company wants to conduct a survey to determine the proportion of its male employees who practice yoga on a daily basis. Two of its regional offices are chosen at random and all of the male employees at each office are surveyed. The plan is an example of which type of sampling?

Which of the following is a key distinction between well designed experiments and observational studies?

A local TV station is interested in how citizens in a small town feel about the increased sales tax proposed by the city council. The question "Are you in favor of the proposed sales tax increase that will be used to improve the sidewalks and streets in downtown?" was shown on the screen during the evening news broadcast and viewers were instructed to text their answer to the number given on the screen. This survey method could produce biased results for all of the following reasons except:

In a certain school, students can choose whether to eat in the school’s cafeteria. A reporter working for the school’s newspaper polled students on their reactions to changes in the menu at the cafeteria. For each student leaving the cafeteria in one 20-minute time period, the reporter used a die to determine whether to stop the student and ask how he or she felt about the new menu. In the reporter’s article it was stated that a random sample of the students showed that 23% of the school’s student population was happy with the new menu. Which of the following statements is true?

In a certain school, students can choose whether to eat in the school’s cafeteria. A reporter working for the school’s newspaper polled students on their reactions to changes in the menu at the cafeteria. For each student leaving the cafeteria in one 20-minute time period, the reporter used a die to determine whether to stop the student and ask how he or she felt about the new menu. In the reporter’s article it was stated that a random sample of the students showed that 23% of the school’s student population was happy with the new menu. Which of the following statements is true?

To check the effect of hot temperatures on the elasticity of two brands of rubber bands, one box of Brand A and one box of Brand B rubber bands are tested. Ten bands from the Brand A box are placed in a warm car in the sun for two hours and ten bands from the Brand B box are kept at room temperature. The amount of stretch before the breakage is measured on each rubber band, and the mean for the hot bands is compared to the mean for the others. Is this a good experimental design?

A group of lobbyists has a list of 100 senators. They decide to talk to every 7th senator on the list about their position on farm subsidies.

The president of a college randomly selects 2 students from each department to serve on a student advisory board.

State the type of sample.

In order to determine the average IQ of ninth-grade students, a school psychologist obtains a list of all schools in the local public school system. She randomly selects five of these schools and administers an IQ test to all ninth-grade students at the selected schools.

The superintendent of a small district has randomly chosen 15 faculty members at a middle school to personally ask if they feel the superintendent is doing a solid job of leading the district. Which sampling design flaw describes this scenario

The principal of a high school makes an announcement that all students who are interested in planting more trees at the school, should swing by and tell the secretary when they would like to try and plant some trees. Which sampling design best describes the scenario

An opinion poll company in North Dakota sends out their surveyors to knock on doors in Fargo from 10 a.m. to 4 p.m. Which sampling design flaw best describes the scenario

A school newspaper is going to investigate students' perceptions regarding the campus security guards. They plan to survey 100 students at the school. The editor-in-chief tells his staff that he is worried about undercoverage bias created by chronically truant students. His concern is...

In a Japanese study, "researchers look at 35 people with lower back pain who were enrolled in an aquatic exercise program, which included swimming and walking in a pool. Almost all of the patients showed improvements after six months, but the researchers found that those who participated at least twice weekly showed more significant improvement than those who went only once per week."