A physical therapist wants to determine the difference in the proportion of men and women who participate in regular, sustained physical activity. What sample size should be obtained if she wishes the estimate to be within 3 percentage points with 95% confidence, assuming that (a) she uses the 1998 estimates of 21.9% male and 19.7% female from the U.S. National Center for Chronic Disease Prevention and Health Promotion? (b) she does not use any prior estimates?
> Researchers wanted to know whether there was a difference in comprehension among students learning a computer program based on the style of the text. They randomly divided 36 students of similar educational level, age, and so on, into two groups of 18 ea
> According to Martin Boon of ICM Limited, a polling firm in Britain, in 1995 it took 3000 to 4000 phone calls to obtain a sample of size 2000. Today, it takes over 30,000 calls. To reduce costs, more polling is done using robocalls and Internet-based poll
> Student ID number
> Researchers wanted to determine if carpeted rooms contained more bacteria than uncarpeted rooms. To determine the amount of bacteria in a room, researchers pumped the air from the room over a Petri dish at the rate of 1 cubic foot per minute for eight ca
> Researchers wanted to determine whether the reaction time (in seconds) of males differed from that of females to a go/no go stimulus. The researchers randomly selected 20 females and 15 males to participate in the study. The go/no go stimulus required th
> Ramp metering is a traffic engineering idea that requires cars entering a freeway to stop for a certain period of time before joining the traffic flow. The theory is that ramp metering controls the number of cars on the freeway and the number of cars acc
> Researchers Brian Wansink and Junyong Kim randomly gave 157 moviegoers a free medium (120 grams) or large (250 gram) bucket of popcorn before entering a movie. After the show, the researchers measured how much popcorn the moviegoers consumed. The 77 indi
> Two Dutch researchers conducted a study in which two groups of students were asked to answer 42 questions from Trivial Pursuit. The students in group 1 were asked to spend 5 minutes thinking about what it would mean to be a professor, while the students
> Do business travelers walk at a different pace than leisure travelers? Researcher Seth B. Young measured the walking speed of business and leisure travelers in San Francisco International Airport and Cleveland Hopkins International Airport. His findings
> Do people walk faster in the airport when they are departing (getting on a plane) or when they are arriving (getting off a plane)? Researcher Seth B. Young measured the walking speed of travelers in San Francisco International Airport and Cleveland Hopki
> Testosterone is a steroid in men that affects sex drive, bone, and muscle mass. Researchers wanted to determine the impact of marriage on testosterone levels in males. Source: Stine A. Hogmboe et. al., “Influence of Marital Status on Testosterone Levels—
> A researcher with the Department of Education followed a cohort of students who graduated from high school in 1992, monitoring the progress the students made toward completing a bachelor’s degree. One aspect of his research was to determine whether stude
> Test whether / level of significance for the given sample data.
> Many national polls are based on random-digit dialing (RDD). In this method, a computer randomly generates a phone number in the hopes of reaching an individual at his/her residence. In registration-based sampling (RBS), voter files are used to obtain a
> Test whether /level of significance for the given sample data.
> (a) Test whether /level of significance for the given sample data. (b) Construct a 95% confidence interval about /
> (a) Test whether /level of significance for the given sample data. (b) Construct a 90% confidence interval about /
> (a) Test whether /level of significance for the given sample data. (b) Construct a 95% confidence interval about /
> An experiment was conducted in which 16 ten-month-old babies were asked to watch a climber character attempt to ascend a hill. On two occasions, the baby witnesses the character fail to make the climb. On the third attempt, the baby witnesses either a he
> (a) Determine di = Xi - Yi for each pair of data. (b) Compute / (c) Test if /level of significance. (d) Construct a 99% confidence interval about the population mean difference /
> (a) Determine di = Xi - Yi for each pair of data. (b) Compute / (c) Test if / level of significance. (d) Construct a 95% confidence interval about the population mean difference /
> A researcher wants to show the mean from population 1 is less than the mean from population 2 in matched-pairs data. If the observations from sample 1 are Xi and the observations from sample 2 are / then the null hypothesis is / and the alternative hypot
> A researcher wants to show the mean from population 1 is less than the mean from population 2 in matched-pairs data. If the observations from sample 1 are Xi and the observations from sample 2 are /then the null hypothesis is /and the alternative hypothe
> You are a passenger in a single-propeller-driven aircraft that experiences engine failure in the middle of a flight. The pilot wants to maximize the distance that the plane can glide to increase the likelihood of finding a safe place to land. To accompli
> Consider this question from a recent Gallup poll: Which of the following approaches to solving the nation’s energy problems do you think the U.S. should follow right now—[ROTATED: emphasize production of more oil, gas and coal supplies (or) emphasize mor
> Octane is a measure of how much fuel can be compressed before it spontaneously ignites. Some people believe that higher-octane fuels result in better gas mileage for their cars. To test this claim, a researcher randomly selected 11 individuals (and their
> Chicago has installed cameras at various intersections through the city. The cameras photograph the license plate of any car engaging in a moving violation (such as driving through a red light or failing to stop completely prior to turning on red). Resea
> An automotive researcher wanted to estimate the difference in distance required to come to a complete stop while traveling 40 miles per hour on wet versus dry pavement. Because car type plays a role, the researcher used eight different cars with the same
> To illustrate the effects of driving under the influence (DUI) of alcohol, a police officer brought a DUI simulator to a local high school. Student reaction time in an emergency was measured with unimpaired vision and also while wearing a pair of special
> The following data represent the daily rental for a compact automobile charged by two car rental companies, Thrifty and Hertz, in ten locations. Test whether Thrifty is less expensive than Hertz at the = 0.1 level of significance. Note: A normal probab
> The manufacturer of hardness testing equipment uses steel-ball indenters to penetrate a metal that is being tested. However, the manufacturer thinks it would be better to use a diamond indenter so that all types of metal can be tested. Because of differe
> A quality-control manager at an amusement park feels that the amount of time that people spend waiting in line for the American Eagle roller coaster is too long. To determine if a new loading/unloading procedure is effective in reducing wait time in line
> To test the belief that sons are taller than their fathers, a student randomly selects 13 fathers who have adult male children. She records the height of both the father and son in inches and obtains the following data. Does the evidence suggest that son
> A Secchi disk is an 8-inch-diameter weighted disk that is painted black and white and attached to a rope. The disk is lowered into water and the depth (in inches) at which it is no longer visible is recorded. The measurement is an indication of water cla
> It is a commonly held belief that SUVs are safer than cars. If an SUV and car are in a collision, does the SUV sustain less damage (as suggested by the cost of repair)? The Insurance Institute for Highway Safety crashed SUVs into cars, with the SUV movin
> Suppose you are reading an article at psychcentral.com and the following text appears in a pop-up window: What tactic is the company using to increase the response rate for its survey?
> In an experiment conducted online at the University of Mississippi, study participants are asked to react to a stimulus. In one experiment, the participant must press a key on seeing a blue screen and reaction time (in seconds) to press the key is measur
> The following data represent the muzzle velocity (in feet per second) of rounds fired from a 155-mm gun. For each round, two measurements of the velocity were recorded using two different measuring devices, with the following data obtained: (a) Why are t
> In a prospective cohort study, 20 patients with alopecia (hair loss) had platelet-rich plasma (PRP) injected in their scalps. After three months, the mean difference in hair density (after before) was 170.70 hairs per square centimeter with a standard de
> A researcher wishes to determine the effects of alcohol on people’s reaction time to a stimulus. She randomly divides 100 people aged 21 or older into two groups. Group 1 is asked to drink 3 ounces of alcohol, while group 2 drinks a placebo. Both drinks
> A sociologist wishes to compare the annual salaries of married couples in which both spouses work and determines each spouse’s annual salary.
> A sampling method is _____ when the individuals selected for one sample are used to determine the individuals in the second sample.
> A sampling method is ______ when the individuals selected for one sample do not dictate which individuals are selected to be in a second sample.
> Explain the difference between an independent and dependent sample
> Why do we use a pooled estimate of the population proportion when testing a hypothesis about two proportions? Why do we not use a pooled estimate of the population proportion when constructing a confidence interval for the difference of two proportions?
> On April 12, 1955, Dr. Jonas Salk released the results of clinical trials for his vaccine to prevent polio. In these clinical trials, 400,000 children were randomly divided in two groups. The subjects in group 1 (the experimental group) were given the va
> Consider the following two questions: (a) Do you believe that the government should or should not be allowed to prohibit individuals from expressing their religious beliefs at their place of employment? (b) Do you believe that the government should or sh
> Stock fund managers are investment professionals who decide which stocks should be part of a portfolio. In an article in the Wall Street Journal (“Not a Stock-Picker’s Market,” WSJ, January 25, 2014), the performance of stock fund managers was considered
> An educator wants to determine the difference between the proportion of males and females who have completed four or more years of college. What sample size should be obtained if she wishes the estimate to be within 2 percentage points with 90% confidenc
> A random sample of single males and single females (aged 21 to 76) was obtained by a group called Singles in America. The sample includes those currently separated, divorced, or widowed. The subjects were given a trait and asked to respond whether the tr
> Psychologists asked students to read two sentences about hypothetical politicians. One group of students read, “Last year, Mark was having an affair with his assistant and was taking hush money from a prominent constituent.” Let’s call this sentence A. S
> In the Sullivan Statistics Survey I, respondents were asked, “Would you be willing to pay higher taxes if the tax revenue went directly toward deficit reduction?” Treat the respondents as a simple random sample of adult Americans. The results of the surv
> The data set “Tornadoes_2017” located at www.pearsonhighered.com/ sullivanstats contains a variety of variables that were measured for all tornadoes in the United States in 2017. (a) Is there a difference in the proportion of F0 tornadoes in Texas versus
> In March 2003, the Pew Research Group surveyed 1508 adult Americans and asked, “Do you believe the United States made the right or wrong decision to use military force in Iraq?” Of the 1508 adult Americans surveyed, 1086 stated the United States made the
> OPDIVA is a drug developed by Brystol-Meyers Squib that is meant to treat metastatic melanoma, which is the worst form of skin cancer. Survival rates for patients with this cancer are 6 to 10 months. Historically, patients with metastatic melanoma were t
> In clinical trials for treatment of a skin disorder, 642 of 2105 patients receiving the current standard treatment were cured of the disorder and 697 of 2115 patients receiving a new proposed treatment were cured of the disorder. (a) Does the new procedu
> Consider the following two questions: (a) Currently, social media companies, such as Facebook, profit by selling user data. Do you believe the government should regulate the ability of social media companies to sell user data? (b) Would you be willing to
> In clinical trials of the allergy medicine Clarinex (5 mg), 3307 allergy sufferers were randomly assigned to either a Clarinex group or a placebo group. It was reported that 50 out of 1655 individuals in the Clarinex group and 31 out of 1652 individua
> Researchers at Harris Interactive wondered if there was a difference between males and females in regard to whether they typically buy name-brand or store-brand products. They asked a random sample of males and females the following question: “For each o
> Researchers at Harris Interactive wondered if there was a difference between males and females in regard to some common annoyances. They asked a random sample of males and females, the following question: “Are you annoyed by people who repeatedly check t
> The body mass index (BMI) of an individual is a measure used to judge whether an individual is overweight or not. A BMI between 20 and 25 indicates a normal weight. In a survey of 750 men and 750 women, the Gallup organization found that 203 men and 270
> The Harris Poll conducted a survey in which they asked, “How many tattoos do you currently have on your body?” Of the 1205 males surveyed, 181 responded that they had at least one tattoo. Of the 1097 females surveyed, 143 responded that they had at least
> The Pew Research Group conducted a poll in which they asked, “Are you in favor of, or opposed to, executing persons as a general policy when the crime was committed while under the age of 18?” Of the 580 Catholics surveyed, 180 indicated they favored cap
> In October 1947, the Gallup organization surveyed 1100 adult Americans and asked, “Are you a total abstainer from, or do you on occasion consume, alcoholic beverages?” Of the 1100 adults surveyed, 407 indicated that they were total abstainers. In a re
> In randomized, double-blind clinical trials of Prevnar, infants were randomly divided into two groups. Subjects in group 1 received Prevnar, while subjects in group 2 received a control vaccine. After the second dose, 137 of 452 subjects in the experimen
> The drug Prevnar is a vaccine meant to prevent certain types of bacterial meningitis, typically administered to infants around 2 months. In randomized, double-blind clinical trials of Prevnar, infants were randomly divided into two groups. Subjects in gr
> x1 = 804, n1 = 874, x2 = 892, n2 = 954, 95% confidence
> The General Social Survey asked, “About how often did you have sex in the past 12 months?” About 47% of respondents indicated they had sex at least once a week. In an internet survey for a marriage and family wellness center, respondents were asked, “How
> x1 = 28, n1 = 254, x2 = 36, n2 = 301, 95% confidence
> x1 = 109, n1 = 475, x2 = 78, n2 = 325, 99% confidence
> x1 = 368, n1 = 541, x2 = 421, n2 = 593, 90% confidence
> Test whether / /
> Test whether / /
> Test whether / /
> Test whether / /
> A psychologist wants to know whether subjects respond faster to a go/no go stimulus or a choice stimulus. With the go/no go stimulus, subjects must respond to a particular stimulus by pressing a button and disregard other stimuli. In the choice stimulus,
> An educator wants to determine whether a new curriculum significantly improves standardized test scores for third grade students. She randomly divides 80 third-graders into two groups. Group 1 is taught using the new curriculum, while group 2 is taught u
> A political scientist wants to know how a random sample of 18- to 25-year-olds feel about Democrats and Republicans in Congress. She obtains a random sample of 1030 registered voters 18 to 25 years of age and asks, “Do you have favorable/ unfavorable [ro
> Surveys tend to suffer from low response rates. Based on past experience, a researcher determines that the typical response rate for an e-mail survey is 40%. She wishes to obtain a sample of 300 respondents, so she e-mails the survey to 1500 randomly sel
> The Gallup Organization asked 1050 randomly selected adult Americans age 18 or older who consider themselves to be religious, “Do you believe it is morally acceptable or morally wrong [rotated] to conduct medical research using stem cells obtained fr
> A simple random sample of size n = 200 individuals with a valid driver’s license is asked if they drive an American-made automobile. Of the 200 individuals surveyed, 115 responded that they drive an American-made automobile. Determine if a majority of th
> A simple random sample of size n = 19 is drawn from a population that is normally distributed. The sample mean is found to be 0.8, and the sample standard deviation is found to be 0.4. Test whether the population mean is less than 1.0 at the = 0.01 lev
> Researchers measured regular testosterone levels in a random sample of athletes and then measured testosterone levels prior to an athletic event. They wanted to know whether testosterone levels increase prior to athletic events.
> In 2014, of the 37 million borrowers who have outstanding student loan balances, 14% have at least one past due student loan account. A researcher with the United States Department of Education believes this proportion has increased since then. Sourc
> According to the Pew Research Center, 55% of adult Americans support the death penalty for those convicted of murder. A social scientist wondered whether a higher proportion of adult Americans with at least a bachelor’s degree support the death penalty f
> An official with the Internal Revenue Service wished to estimate the proportion of high-income (greater than $100,000 annually) earners who under-reported their net income (and, therefore, their tax liability).
> A researcher wanted to estimate the average length of time mothers who gave birth via Caesarean section spent in a hospital after delivery of the baby.
> An investigator with the Food and Drug Administration wanted to determine whether a typical bag of potato chips contained less than the 16 ounces claimed by the manufacturer.
> Suppose you wish to determine if the mean IQ of students on your campus is different from the mean IQ in the general population, 100. To conduct this study, you obtain a simple random sample of 50 students on your campus, administer an IQ test, and recor
> To determine the public’s opinion of the police department, the police chief obtains a cluster sample of 15 census tracts within his jurisdiction and samples all households in the randomly selected tracts. Uniformed police officers go door to door to con
> A survey from the Gallup organization asked, “What do you think is the ideal number of children for a family to have?” Go to www.pearsonhighered.com/sullivanstats to obtain the data file 10_4_18 using the file format of your choice for the version of the
> According to Crestmont Research, the stock market has been up in 53.7% of all trading days over the past 50 years. A stock is up if the price per share increases in value day-over-day. An investor wondered whether the proportion of days Amazon stock was
> Suppose the mean wait-time for a telephone reservation agent at a large airline is 43 seconds. A manager with the airline is concerned that business may be lost due to customers having to wait too long for an agent. To address this concern, the manager d
> Politicians often form their positions on various policies through polling. Suppose the U.S. Congress is considering passage of a tax increase to pay down the national debt and national polls suggest the general population is equally split on the matter.
> Student loan debt has reached record levels in the United States. In a random sample of 100 individuals who have student loan debt, it was found the mean debt was $23,979 with a standard deviation of $31,400. Data based on results from the Federal Reserv
> According to the research firm Toluna, the proportion of individuals who text while driving is 0.26. Suppose a random sample of 60 individuals are asked to disclose if they text while driving. Results of the survey are shown next, where 0 indicates no an
> According to the National Sleep Foundation, children between the ages of 6 and 11 years should get 10 hours of sleep each night. In a survey of 56 parents of 6 to 11 year olds, it was found that the mean number of hours the children slept was 8.9 with a
> The Environmental Protection Agency (EPA) states that a 2013 Kia Optima should get 28 miles per gallon, on average. The website www.fueleconomy.gov allows users to report the miles per gallon that they get on their vehicle. Treat the following data as a
> According to the Federal Reserve Bank of Boston, among individuals who had credit cards in 2014, the mean number of cards was 3.5. Treat the individuals who have credit cards in the SullivanStatsSurveyI as a random sample of credit card holders. Go to ww
> Pass rates for Intermediate Algebra at a community college are 52.6%. In an effort to improve pass rates in the course, faculty of a community college develop a mastery- based learning model where course content is delivered in a lab through a computer p
