Stats final MCQ
Which of the following is an appropriate margin of error for a 99 percent confidence interval to estimate the difference in the population proportion of all users of each treatment who would lose weight?
(A) 2.576 50 + sqrt((0.7)(0.3)/50 + (0.40)(0.60)/40)
A 21-year old college student submits a photo to the website "Guess My Age". At a later date he checks back and thousands of users have made guesses about his age. Of the following, which is the best procedure to investigate whether there is convincing statistical evidence that, on average, he is perceived to be less than 21 years old?
(A) One sample t-test for a mean
Electric vehicles make up a very small proportion of the overall car market, but by how much has that proportion increased? Independent surveys of randomly selected car dealerships were completed, with 0.1% of the 10,000 cars sold in the 2012 sample being electric vehicles, and 0.5% percent of the 20,000 cars in the 2016 sample being electric vehicles. Which of the following represents a 95% confidence interval for the change in the proportion of electric cars sold from 2012 to 2016?
(A) (0.005 − 0.001) ± 1.96 (sqrt ((0.005(1-0.005)/20,000) + 0.001(1-0.001)/10,000)))
According to a study, 91% of all adults have a cell phone. An employee of a cell phone company attends a community event and has a special offer to give to first time cell phone owners. If she randomly selects adults in attendance at the event and cell phone ownership is independent from adult to adult, what is the probability that she asks 21 adults total to find the first one that does not own a cell phone?
(A) (0.91) (0.09)
Calculate a 99 percent confidence interval for the difference in mean price for a quarter pound hamburger in the United States and Japan.
(A) (4.53 − 4.01) ± 2.983 sqrt(0.24^2/15 + 0.38^2/10)
The weight of a single bag checked by an airplane passenger follows a distribution that is right skewed with a mean of 38 pounds and a standard deviation of 6.2 pounds. If a random sample of 96 bags is selected, what is the probability that the average weight of the bags exceeds 40 pounds?
(A) 0.0008
Employees that work at a fish store must measure the level of nitrites in the water each day. Nitrite levels should remain lower than 5 ppm as to not harm the fish. The nitrite level varies according to a distribution that is approximately normal with a mean of 3 ppm. The probability that the nitrite level is less than 2 ppm is 0.0918. Which of the following is closest to the probability that on a randomly selected day the nitrite level will be at least 5 ppm?
(A) 0.0039
He selects a random sample of 500 containers of orange juice and determined the percentage of each that is water. He plans to conduct a significance test at the = 0.01 level to see if there is convincing evidence that the proportion of water added is different from 0.50. What is the probability that the inspector makes a Type I error?
(A) 0.01
Airlines must be aware of the weight of the aircraft plus everything on board. Based on thousands of flights, the mean and standard deviation for the weights of several items are shown in the table. The weights of the airplane, people/luggage, and fuel are assumed to be independent. Let the random variable T represent the total weight of the plane, people/luggage, and fuel for a randomly selected flight. Which of the following is closest to the standard deviation of T?
(A) 2.45 tons
Assuming all conditions for inference are met, which of the following is a 90 percent confidence interval for the mean projected career earnings for graduates with degrees in education?
(A) 2.5 ± 1.7110.4/sqrt25
A chi-square goodness of fit test was conducted to determine whether the data provide convincing evidence that the wheel is not fair. The test statistic was 37.52. Which of the following statements is true?
(B) At the significance level α = 0.05, the data provide convincing evidence that the wheel is not fair.
The difference for each pair is calculated (sugar - sugar-free). A 90% confidence interval for the mean difference in reading times is (-5.8, 0.15). Which statement is correct?
(B) Because the confidence interval includes 0, we don't have convincing evidence that sugar causes faster reading times, on average.
If the experiment uses a block design based on the size of the trucks, which of the following is not a possible list of trucks that receive the first treatment?
(B) Colorado, Canyon, Titan, Tacoma
Consider the stemplot, which gives the number of people attending a matinee show at the local theatre for 26 days. Which of the following is true?
(B) II . half of the data values are larger than 54
Which statistic is the best estimator of the parameter?
(B) Statistic B because A and B are unbiased but B has lower variability.
Which of the following statements is the best interpretation of the 99 percent confidence level?
(B) We would expect about 99 of the 100 confidence intervals to contain the proportion of all registered voters who plan to vote for the Republican candidate.
Scatterplot for the nine french fry orders. How would this tenth data point affect the slope and correlation in this scenario?
(B) slope increases, correlation increases
Assuming all conditions for inference were met, which of the following is a 90 percent confidence interval for the proportion of patients that will experience side effects while taking medication X?
(C) (0.2849, 0.3951)
Which of the following expressions represents the expected count of leased SUVs?
(C) (35)(30)/95
Battery life has a strong, negative, linear relationship with temperature. If regression line using x = temp explains 90% of the variation in battery life, which of the following must be r?
(C) - 0.95
Assuming that all conditions for inference are met, which of the following is a 95 percent confidence interval for the average change in the number of billable hours for each increase of 1 hour spent walking?
(C) -0.245 ± 2.160(0.205)
The scatterplot below shows data for the nine French Fry orders from the previous problem with the least-squares regression line. Which of the following is the best estimate of the value of the residual for the point indicated by the arrow?
(C) -60
When playing the card game Blackjack, multiple decks are used and reshuffled often so that the outcomes of the cards dealt are approximately independent. When a player receives two cards that are a combination of an ace and a face card, this is called a "natural blackjack" and automatically wins. A natural blackjack should occur in 4.5% of the rounds played. What is the probability that a player plays 20 rounds of Blackjack and gets two or more natural blackjacks?
(C) 0.227
What is the probability a randomly selected LGA refrigerator is at least one year old and no longer works?
(C) 0.480
A pollster asked 100 people "If money was not a factor, how many children would you like to have?" What is the probability that the number of children a randomly selected person from this sample would like to have is less than the mean of X?
(C) 0.51
Which of the following represents the 95% confidence interval for the slope of the regression line relating BMI and percent body fat for the population of adult males?
(C) 1.695 ± 2.306(0.2280)
Do stain-polyurethane mixes protect wood as well as stain and polyurethane applied in separate coats? Five types of wood will be used, with two boards of each type of wood. One board of each type of wood (randomly selected) will have the stain-polyurethane mix applied to it, and the other will have stain and polyurethane applied in separate coats. Each board will have water poured on it, and the amount of water retained will be measured. Which significance test is most appropriate?
(C) A matched-pair t-test for a mean difference
Which of the following statements is true?
(C) A sampling distribution is the distribution of a statistic calculated from all possible samples of the same size from the same population.
Household income in the United States is strongly skewed to the right. The current presidential administration claims that the mean household income is greater than it has ever been in the past. An independent contractor will obtain a random sample of 100 households in the United States and will calculate the mean household income. Which of the following statements is true?
(A) The sampling distribution of the sample mean household income is approximately normal because the sample size of 100 is greater than 30.
With all conditions for inference met, a significance test was conducted and a P-value of 0.045 was obtained. Which of the following statements is the most appropriate conclusion using a significance level of α = 0.05?
(A) There is convincing statistical evidence that the mean salary for all recent college graduates from the small college is greater than $45,327.
After completing a statistical analysis of a survey of 40 students, the principal of North High School made the following conclusion: reject the null hypothesis; there is convincing evidence that more than 50% of students support a schedule change to have lunch occur earlier in the day. Which error could have been committed?
(A) Type I error: Conclude that more than 50% of students want earlier lunch, when 50% or less want earlier lunch.
A random sample of households is taken. For each household, the # of hours spent watching TV and power consumption during the day are recorded. (Shows a pic of a calculator output) Which of the following is a correct interpretation of r^2?
(A) number of hours spent watching TV explains 30% of the variability in power consumption
Which of the following is closest to the standard error for the test statistic?
(A) sqrt(0.711(1-0.711)/40 + 0.8(1-0.8)/50)
Which of the following is the test statistic for the appropriate test to determine if the average amount of soda that is contained in their 20-ounce soda bottles is significantly less than 20-ounces?
(A) t = 19.4-20/0.25/sqrt(n)
Two variables x and y have a correlation of 0.75. If x has a mean of 25 and a SD of 3, and y has a mean of 12 and a SD of 6, which of the following is the least-squares regression line for the two variables?
(A) y = -25.5 + 1.5x
A random sample of households is taken. For each household, the # of hours spent watching TV and power consumption during the day are recorded. (Shows a pic of a calculator output) Which of the following is the equation of the regression line?
(A) y = 19.31 + 0.891x
The scores on the verbal section of the Graduate Records Examination (GRE) are approximately normally distributed with a mean of 150 and a standard deviation of 8.5. What is the probability that a randomly selected score on the verbal section is higher than 165?
(B) 0.039
A large-sample 95 percent confidence interval for the proportion of credit card customers that have reported fraudulent charges on their account is (0.028, 0.086). What is the point estimate for the proportion of all credit card customers that have reported fraudulent charges on their account?
(B) 0.057
A company advertises two car tire models. The number of thousands of miles that the standard model tires last has a mean and standard deviation . The number of miles that the extended life tires last has a mean and standard deviation . If mileages for both tires follow a normal distribution, what is the probability that a randomly selected standard model tire will get more mileage than a randomly selected extended life tire?
(B) 0.123
At a summer camp, 72% of the campers participate in rope climbing and 26% participate in canoeing. 83% of the campers participate in rope climbing, canoeing, or both. What is the probability that a randomly selected camper participates in both rope climbing and canoeing?
(B) 0.15
The finishing times of a 5K race run by competitive male runners age 15-18 are approximately normal distribution with a mean time of 18 minutes and a standard deviation of 2 minutes. A particularly tough 5K race tends to take these same runners 4.5 additional minutes. To earn a completion medal in this particular 5K race, the runner must complete the race within 25 minutes. Approximately, what percent of competitive male runners in the 15-18 age bracket typically do not earn a completion medal at this race?
(B) 10.56%
Using the least-squares regression line y = -25.5 + 1.5x, what is the residual for the data point at (28,19)?
(B) 2.5
The box plot below summarizes the heights of a sample of 200 3-year old males in the US. Which statement is false?
(B) 25 children had heights greater than 98cm
The DNR is planning a study to determine whether breakwaters help decrease erosion at a large lake. They divide the shoreline into 100- foot plots, installing some with breakwaters and some without. However, the east and west shorelines of this lake receive very different wave patterns due to the wind. The DNR suspects this will affect the responses to the breakwaters. Because of this, the DNR plans to treat each shoreline as a different group. This study is an example of
(B) A blocked design experiment.
The citizen wants to find a confidence interval that can be used to estimate the number of additional crimes that can be expected to be reported for each degree that the daily high temperature increases with 95% confidence. Which of the following is the most appropriate procedure for such an investigation?
(B) A linear regression t-interval for slope
Twenty volunteers with high cholesterol were selected for a trial to determine whether a new diet reduces cholesterol. The volunteers were given a low-carb, low-calorie diet. After 8 weeks of the diet, the average cholesterol of the volunteers dropped a significant amount. This study is an example of
(B) An uncontrolled experiment.
Daren and Josh are pretty good free throw shooters. Daren makes 75% of the free throws he attempts. Josh makes 80% of his free throws. Suppose we take separate random samples of 50 free throws each from Daren and Josh, and record the proportion of free throws that are made by each. Which of the following best describes the sampling distribution of p^D − p^J ?
(B) Approximately normal, with mean -0.05 and standard deviation 0.083
In a large school district, it is known that 25% of all students entering kindergarten are already reading. A simple random sample of 10 new kindergarteners is drawn. What is the probability that fewer than three of them are able to read?
(D) 0.5256
An advertiser wants to find convincing evidence that television viewers remember more than 4 commercials, on average, after watching a 30 minute TV program. They take a random sample of 100 television viewers and ask them how many commercials they could remember after watching a 30 minute TV program. The appropriate t-test was conducted, which resulted in a P-value of 0.15. Assuming all conditions were met, which of the following is an appropriate conclusion?
(C) Because the P-value is greater than 0.01, at the 1% significance level, there is not convincing evidence that television viewers remember more than 4 commercials, on average, after watching a 30 minute TV program.
Let represent the average difference in time (actual time - estimated time) it took to complete the problem for all students. She would like to investigate whether there will be convincing statistical evidence that the students overestimate the time it took to complete the problem, on average. Which of the following is the correct hypotheses for this test?
(C) H0: μ = 0 and Ha : μ < 0
Which of the following relationships between two variables could be described using correlation, r?
(C) High Temperature of the day and number of zoo visitors that day
For which of the above samples would it be appropriate to use -procedures for inference for the population mean?
(C) I and III
A random sample of 18 adults, chosen from the 1500 adults in the town, took a survey asking their opinion on a recent property tax change. 25% of those who responded said they were in favor of the change. The company running the survey wants to construct a confidence interval estimating the proportion of all adults in the town who support the change. Which of the conditions for inference have been satisfied?
(C) I and III I. random condition III. 10% condition
A distribution has a shape that is strongly skewed left. Which is most likely true?
(C) Mean < Median
Using data collected from 1981 to 2010 for Ann Arbor, MI (GO BLUE!), the average "high" temperature for days in July has a mean of 28.9° Celsius with a standard deviation of 3.3° Celsius. What are the mean and standard deviation if the temperatures are converted to degrees Fahrenheit? Note: Fahrenheit = 1.8× Celsius +32
(C) Mean is 84.02°F, Standard deviation is 5.94°F.
A social media developer wants to determine if the proportion of teenagers who use Facebook is the same as the proportion of teenagers who use Snapchat. She takes a random sample of 100 teenagers and finds that 75 of the 100 students use Facebook and 89 of the 100 students use Snapchat. Would it be reasonable for the social media developer to construct a 95% confidence interval for the true difference in proportion of teenagers that use Facebook and Snapchat?
(C) No, the two samples are not independent.
Based on the graph of the distribution of favorite math class for students and teachers at East Kentwood High School, which of the following statements is true?
(C) When combining students and teachers, AP Stats has the highest overall proportion who chose it as their favorite math class
An AP stats class starts a project to estimate the avg number of hours a student sleeps per night. Their high school has 1200 students, and they take a sample of the first 120 students that arrive at school on a particular day. They ask each of the 120 students how many hours of sleep on avg. Which of the following statements is an accurate description of the elements of this survey?
(C) sample: the 120 students surveyed. Population: the 1200 students at the hs parameter of interest: the avg number of hours a student at this high school sleeps per night.
The Career Placement department at a university wants to administer a survey to determine student awareness of the resources offered. The department expects that student awareness of the Career Placement resources will vary significantly depending on how many years a student has attended the university, so they plan to randomly select 30 freshmen, 30 sophomore, 30 juniors, and 30 seniors. This type of sample can be best described as a
(C) stratified sample.
A club bowling team had 12 members. The first ten members bowl a game with an avg score of 156. If you know the next two members bowl scores of 173 and 151, do you have enough information to find the total of all 12 scores?
(C) yes, 1884
By one estimate, 3% of all Siberian Husky puppies are born with two different colored eyes (called heterochromia iridum). For random samples of 50 Siberian Husky puppies, what are the mean and standard deviation of the number of puppies that will have two different colored eyes?
(C) μ = 1.5, σ = 1.206
In a large city, 46% of adults support the local football team building a new stadium. If a poll is taken from a random sample of 80 adults in the large city, which of the following properly describes the sampling distribution of the sample proportion of adults who support the stadium?
(C) μp^ = 0.46, σp^ = 0.056, the distribution is approximately normal.
Which of the following describe the sampling distribution of the difference in sample means?
(C) μxo-xk = 1260, σxo-xk = 6259.91, the distribution is approximately normal.
The inspector would like to detect if the true mean diameter happens to reach 1.95 cm at a significance level of a = 0.01. He determines the power of this test to be 0.9228. What is the probability that the inspector will make a Type II Error?
(D) 0.0772
A dice game at a local carnival uses a 10-sided die which has been rigged. The even numbered outcomes (2, 4, 6, 8, and 10) have been made lighter so that they are three times more likely to occur as the odd numbered outcomes (1, 3, 5, 7, and 9). A player that rolls an odd number wins the game. What is the probability of winning this game?
(D) 0.25
The table below shows how high school students in four grade levels ate their lunch on a particular fat - purchased in the cafeteria, brought a bag lunch, or purchased lunch off campus. What is the approximate proportion of Juniors that purchased lunch off-campus?
(D) 0.27
According to school records, your school's softball team wins 62% of the time when they play a game on their home field and 26% of the time when they play at the other team's field. This season, they play 45% of their games at their home field. Assuming this team wins at the same pace as previous teams, what is the probability that they win a randomly selected game this season?
(D) 0.422
The heights of all adult males in Croatia are approximately normally distributed with a mean of 180 cm and a standard deviation of 7 cm. The heights of all adult females in Croatia are approximately normally distributed with a mean of 158 cm and a standard deviation of 9 cm. If independent random samples of 10 adult males and 10 adult females are taken, what is the probability that the difference in sample means (males - females) is greater than 20 cm?
(D) 0.7104
A newspaper plans to conduct a survey for the upcoming presidential election in order to estimate the proportion of the population, p, who supports a certain candidate. What is the smallest sample size needed to obtain an estimate that is within 4% of the true proportion p at the 96% confidence level?
(D) 660
A recent report states that 89% of Americans consider themselves above average drivers. A local newspaper is planning on conducting a survey to investigate whether this is true locally. If the newspaper assumes that the 89% claim is true and plans to use the normal approximation to calculate probabilities associated with their sample proportion, which sample size would be most appropriate?
(D) 91
A random sample of 300 balls hit into play in college baseball games is taken. For each ball hit into play, it is recorded whether the ball was hit to the left, center, or right of the field, and whether the ball resulted in a hit or an out. Which of the following is the appropriate null hypothesis to test if there is a relationship between the direction of the ball and if it resulted in a hit or an out?
(D) : The direction of the ball and whether it results in a hit or an out are independent.
A college professor calculates the standard deviation of all the grades from the midterm exams she most recently administered. Which id the best description of the standard deviation?
(D) Approximately the mean distance between the individual grades of the midterm exams and the mean grade of all midterm exams.
A study is conducted to determine if the blue light from a tablet device will affect the fall asleep time of people in various age groups differently. Volunteers for the study are grouped by age: 18-30, 31-50, and 50+. Half of each group is assigned a standard tablet, the other half is assigned a tablet with reduced blue light. People in each group are asked to use the tablet for 10 minutes before bed and their fall asleep time is recorded. Which of the following is correct?
(D) Blocks: the three age groups. Treatments: using the standard tablet or the reduced blue light tablet before bed. Response variable: Time it takes to fall asleep.
A Statistics class from a high school with 4,000 students took a survey of the first 35 students who walked through the front door of the school, and asked how far they traveled to school that day. The class plans to run a one-sample t-test to determine if the average travel distance has increased since last year. The students notice that the sample data are right skewed. Which conditions have been satisfied for the t-test?
(D) II and III II. The sampling distribution of sample means is approximately normal. III. The sample size is small relative to the population.
Diverticulitis is a common intestinal ailment. To test a new medication, a hospital takes 50 volunteers who have a moderate case of the disease. The volunteers are randomly assigned to two treatment groups, one receiving the old medication and one receiving the new medication. The pills are distributed in unmarked pill form so that the patients and medical professionals do not know which medication the patient is taking. Which of the following statements is/are true?
(D) II and III II. The group receiving the old medication serves as a control group. III. This is an example of a double-blind experiment.
Which of the following is an accurate interpretation of this P-value?
(D) If the null hypothesis is true, there is a 24% probability of getting a sample difference in means as far or farther below 0 as the difference found in the samples.
Assuming all conditions for inference are met, do the data provide convincing statistical evidence at the significance level of α = 0.05 that more than two- thirds of the Earth is water?
(D) No, because the P-value of 0.08 is greater than the significance level of 0.05.
A company intends to collect a random sample of size from a population with population proportion of interest . Which of the following situations would result in the smallest standard deviation of the sampling distribution of ?
(D) The population proportion p ≠ 0.5, and the sample size is 2n.
The table below gives information on the number of houses built in three different neighborhoods and in three different decades. Which one of the following statements is false?
(D) The probability that a randomly selected home was built in the 1980s or is in the Oakcrest neighborhood is . 110/220
At a high school, the cafeteria staff provides optional comment cards to students eating in the cafeteria. Students who wish to make a comment can obtain and fill out a comment card and return it to a drop box in the front office. At the end of the semester, the staff analyzes the responses and finds that 72% of the students who filled out a comment card recommend major changes to the food selection. What conclusions can the cafeteria staff draw from these responses?
(D) The responses were from a voluntary response sample, so the cafeteria staff should not use the results to draw any conclusions.
Donner Summit, California, is a popular ski resort area. Over the past 60 years, the annual snowfall totals of Donner Summit have followed a distribution that is strongly skewed right with a mean of 404 inches and a standard deviation of 129 inches. If many samples of size 9 were taken, which of the following would best describe the shape of the sampling distribution of xˉ?
(D) The shape is skewed right but less so than the population distribution.
An AP Statistics class surveys 24 randomly selected female students from their high school, and calculates a 95% confidence interval for the mean height of female students to be 63.4±1.6 inches. Which of the following is a correct interpretation of this interval?
(D) We can be 95% confident that the true mean height of female students at the school is between 61.8 and 65.0 inches.
Major League Baseball (MLB) has recently been evaluating the timing of various events during games in an effort to improve the pace of a game. MLB wants to know how long a mound visit, defined as when a coach pauses the game to visit the pitcher on the mound, takes on average. MLB randomly selects 100 games over the course of a season, and records the length, in seconds, of every mound visit that occurs in that game.
(D) cluster sample.
Data are collected on the amount of fat(in grams) and calories in the french fry orders at nine fast food restaurants. The least-squares regression line for the data is y = 274.34 + 9.55x, where y is the predicted # of calories and x is grams of fat. Which is the correct interpretation of the slope of the least-squares regression line?
(D) for every increase of 1 gram of fat, the predicted calories increase by 9.55
The graph below displays the amount of time to the nearest hour spent on homework per week for a sample of students. Which measures of center and variability would be most appropriate to describe the given distribution?
(D) median and IQR
An analysis of 8 used trucks listed for sale in the 48076 zip code finds that the power model , for price (in thousands of dollars) and miles driven (in thousands), is an appropriate model of the relationship. If a used truck has been driven for 47,000 miles, which of the following is closest to the predicted price for the truck?
(E) $24,800.00
Based on student records, 25% of the students at a large high school have a GPA of 3.5 or better, 16% of the students are currently enrolled in at least one AP class, and 12% of the students have a GPA of 3.5 or better and are enrolled in at least one AP class. If we select one student at random, what is the probability that the student has a GPA lower than 3.5 and is not taking any AP classes?
(E) 0.71
Redundant monitoring means that a signal is sent in multiple forms or paths to reach its intended target. For example, an alarm may be set up to send multiple signals to a security company, each independent of each other in case of failure along one path. If an alarm sends off four signals down different paths, and each has a 0.65 probability of reaching the security company, what is the probability that at least one signal successfully reaches the security company?
(E) 0.985
A study intends to estimate a population mean with an unknown population standard deviation and a sample size of 15. Which of the following is closest to the appropriate critical value to create a 98% confidence interval?
(E) 2.624
Assuming that all conditions for inference are met, which of the following is the appropriate test statistic for testing the null hypothesis that the slope of the population regression line equals 0?
(E) 25.40
According to the Guinness Book of World Records, a woman from Russia, Mrs. Vassilyeva, had 69 children between the years 1725 to 1765. She had 16 pairs of twins, 7 sets of triplets, and 4 sets of quadruplets. Suppose one of the births is randomly selected. Given that Mrs. Vassilyeva gave birth to at least 3 children (triplets), what is the probability that she gave birth to quadruplets?
(E) 4/11
The students of a Statistics class want to estimate how many years it takes for a university professor to earn a PhD. They survey a random sample of 40 professors with PhDs, which results in a sample mean of 5.4 years and a standard deviation of 1.6 years. Which of the following represents the 95% confidence interval for the true mean of the number of years it takes a professor to earn a PhD?
(E) 5.4 ± 2.03(1.6/sqrt40)
A random sample of size n is collected from a considerably larger population of size N. That sample is used to create a 95% confidence interval to estimate a population proportion. Using the same sample proportion, the confidence interval would be narrower if:
(E) A lower confidence level was used.
Forty adult males volunteered to participate in an experiment. Half of them are randomly assigned to take a caffeine supplement before working out, and the other half are assigned to take a placebo before completing the same workout. During the workout, heart rate monitors will be used to measure each participant's heart rate. The study found that those who took a caffeine supplement had significantly higher average pulse rates during the workout. What conclusion can be drawn from the study?
(E) Caffeine supplements will, on average, raise the heart rates of adult males similar to those in this study during a workout similar to the one performed in the experiment.
In the casino game Roulette, a bet on "red" will win if the ball lands on one of the 18 red numbers of the 38 numbers on the wheel, with each number being equally likely. You want to run a simulation that will estimate the probability of a player winning both bets when betting on red twice. Which of the following would be an appropriate setup for the simulation:
(E) I and III I. Use a table of random digits to select one number from 01 to 38 and then a second number from 01 to 38. If the first number is between 01 and 18 and the second number is between 01 and 18, then the player has won both rounds. III. Use a table of random digits to select two numbers 01-19, allowing repeats. If both numbers
A credit card company claims that the mean time the customers spend on hold is 3.5 minutes. An employee of this company believes that customers spend more than 3.5 minutes on hold. A random sample of n = 36 calls is selected and the mean time the customers in this sample spent on hold was 5.15 minutes. All conditions for inference were met and the P-value for the appropriate hypothesis test was 0.031. Which of the following statements is the best interpretation of the P-value?
(E) If the null hypothesis is true, the probability of observing a sample mean of at least 5.15 minutes is 0.031.
A recent article claimed that women are waiting longer to have their first child. The article estimates that the average age of first-time mothers is 26 years old, which is up from 21 years old in 1970. The margin of error for the estimate was 1.5 years. Based on the estimate and the margin of error, which of the following is an appropriate conclusion?
(E) It is plausible that the average age of first-time mothers is 27 years old.
A scatterplot shows a strong, positive, linear relationship between the number of rebounds a basketball team averages and the number of wins that team records in a season.
(E) Rebounds and wins are positively correlated, but we cannot conclude that getting more rebounds caused more wins, on average.
Several students in the AP stats class administered a survey and ask how far students travel to school. Which would not be measured in miles?
(E) Variance
Which statement is true?
(e) boxplots clearly show the five-number summary of a data set