For the hypotheses in Problem 15, the null hypothesis is rejected.
> In 1997, 4% of mothers smoked more than 21 cigarettes during their pregnancy. An obstetrician believes that the percentage of mothers who smoke 21 cigarettes or more is less than 4% today. She randomly selects 120 pregnant mothers and finds that 3 of the
> Professors Honey Kirk and Diane Lerma of Palo Alto College developed a “learning community curriculum that blended the developmental mathematics and the reading curriculum with a structured emphasis on study skills.” In a typical developmental mathematic
> Suppose you are conducting a survey regarding the sleeping habits of students. From a list of registered students, you obtain a simple random sample of 150 students. One survey question is “How much sleep do you get?”
> Researchers looked at studies that were reported in newspapers with the goal of determining whether initial studies had results that could be reproduced. Reproducibility of results means that subsequent analysis confirms the conclusion of the original st
> When the area of the brain responsible for vision is destroyed, individuals experience cortical blindness. Patients with cortical blindness are unaware of any visual stimulus, including light. In a 52-year-old male patient with cortical blindness (as a r
> In an American Animal Hospital Association survey, 37% of respondents stated that they talk to their pets on the telephone. A veterinarian found this result hard to believe, so he randomly selected 150 pet owners and discovered that 54 of them spoke to t
> According to QSR Magazine, Chick-fil-A has the best accuracy of drive thru orders with 96.4% of all its drive thru orders filled correctly. The manager of a competing fast food restaurant wants to advertise that her drive thru is more accurate than C
> According to menstuff.org, 22% of married men have “strayed” at least once during their married lives. (a) Describe how you might go about administering a survey to assess the accuracy of this statement. (b) A survey of 500 married men indicated that 122
> In August 2002, 47% of parents with children in grades K–12 were satisfied with the quality of education the students receive. A recent Gallup poll found that 437 of 1013 parents with children in grades K–12 were satisfied with the quality of education t
> In 2000, 58% of females aged 15 and older lived alone, according to the U.S. Census Bureau. A sociologist tests whether this percentage is different today by obtaining a random sample of 500 females aged 15 and older and finds that 285 are living alone.
> In 1994, 52% of parents with children in high school felt it was a serious problem that high school students were not being taught enough math and science. A recent survey found that 256 of 800 parents with children in high school felt it was a serious p
> In December 2001, 38% of adults with children under the age of 18 reported that their family ate dinner together seven nights a week. In a recent poll, 403 of 1122 adults with children under the age of 18 reported that their family ate dinner together se
> According to the National Highway and Traffic Safety Administration, the proportion of fatal traffic accidents in the United States in which the driver had a positive blood alcohol concentration (BAC) is 0.36. Suppose a random sample of 105 traffic fatal
> An antigun advocate wants to estimate the percentage of people who favor stricter gun laws. He conducts a nationwide survey of 1203 randomly selected adults 18 years old and older. The interviewer asks the respondents, “Do you favor harsher penalties for
> Nexium is a drug that can be used to reduce the acid produced by the body and heal damage to the esophagus due to acid reflux. The manufacturer of Nexium claims that more than 94% of patients taking Nexium are healed within 8 weeks. In clinical trials, 2
> The drug Lipitor is meant to reduce cholesterol and LDL cholesterol. In clinical trials, 19 out of 863 patients taking 10 mg of Lipitor daily complained of flulike symptoms. Suppose that it is known that 1.9% of patients taking competing drugs complain o
> In his book, The Signal and the Noise, Nate Silver analyzed 733 predictions made by experts regarding political events. Of the 733 predictions, 338 were mostly true. (a) Determine the sample proportion of political predictions that were mostly true. (b)
> The website pundittracker.com keeps track of predictions made by individuals in finance, politics, sports, and entertainment. Jim Cramer is a famous TV financial personality and author. Pundittracker monitored 678 of his stock predictions (such as a reco
> Suppose an acquaintance claims to have the ability to determine the birth month of randomly selected individuals. To test such a claim, you randomly select 80 individuals and ask the acquaintance to state the birth month of the individual. If the individ
> Throwing darts at the stock pages to decide which companies to invest in could be a successful stock-picking strategy. Suppose a researcher decides to test this theory and randomly chooses 100 companies to invest in. After 1 year, 53 of the companies wer
> H0: p = 0.4 versus H1: p ≠ 0.4 n = 1000; x = 420; a = 0.01
> H0: p = 0.9 versus H1: p ≠ 0.9 n = 500; x = 440; a = 0.05
> H0: p = 0.25 versus H1: p < 0.25 n = 400; x = 96; a = 0.1
> H0: p = 0.55 versus H1: p < 0.55 n = 150; x = 78; a = 0.1
> The village of Oak Lawn wishes to conduct a study regarding the income level of households within the village. The village manager selects 10 homes in the southwest corner of the village and sends an interviewer to the homes to determine household income
> H0: p = 0.6 versus H1: p < 0.6 n = 250; x = 124; a = 0.01
> H0: p = 0.3 versus H1: p > 0.3 n = 200; x = 75; a = 0.05
> Determine the critical value for a two-tailed test regarding a population proportion at the = 0.05 level of significance.
> Determine the critical value for a left-tailed test regarding a population proportion at the = 0.1 level of significance.
> Determine the critical value for a right-tailed test regarding a population proportion at the = 0.01 level of significance
> Put the following P-values in order from weakest to strongest in terms of evidence against the statement in the null hypothesis. (a) 0.139 (b) 0.083 (c) 0.091 (d) 0.005 (e) 0.019
> If we reject the null hypothesis when the statement in the null hypothesis is true, we have made a Type_____ error.
> _______ is a procedure, based on sample evidence and probability, used to test statements regarding a characteristic of one or more populations.
> (a) A_______ is a statement regarding a characteristic of one or more populations. (b) The________ is a statement of no change, no effect, or no difference. (c) The_______ is a statement we are trying to find evidence to support.
> In your own words, explain the difference between “beyond all reasonable doubt” and “beyond all doubt.” Use these phrases to explain why we never “accept” the statement in the null hypothesis.
> A retail store manager wants to conduct a study regarding the shopping habits of his customers. He selects the first 60 customers who enter his store on a Saturday morning.
> The following is a quotation from Sir Ronald A. Fisher, a famous statistician. For the logical fallacy of believing that a hypothesis has been proved true, merely because it is not contradicted by the available facts, has no more right to insinuate itsel
> What happens to the probability of making a Type II error, b, as the level of significance ,, decreases? Why?
> If the consequences of making a Type I error are severe, would you choose the level of significance, , to equal 0.01, 0.05, or 0.10? Why?
> Designed by Bill Bengen, the 4 percent rule says that a retiree may withdraw 4% of savings during the first year of retirement, and then each year after that withdraw the same amount plus an adjustment for inflation. Under this rule, your retirement savi
> Refer to Problem 16. Researchers must choose the level of significance based on the consequences of making a Type I error. In your opinion, is a Type I error or Type II error more serious? Why? On the basis of your answer, decide on a level of significan
> The manufacturer of Prolong Engine Treatment claims that if you add one 12-ounce bottle of its $20 product, your engine will be protected from excessive wear. An infomercial claims that a woman drove 4 hours without oil, thanks to Prolong. Consumer Repor
> According to the Centers for Disease Control, 15.2% of American adults experience migraine headaches. Stress is a major contributor to the frequency and intensity of headaches. A massage therapist feels that she has a technique that can reduce the fre
> According to the Centers for Disease Control and Prevention, 20.8% of high school students currently use electronic cigarettes. A high school counselor is concerned the use of e-cigs at her school is higher. (a) Determine the null and alternative hypothe
> According to popcorn.org, the mean consumption of popcorn annually by Americans is 54 quarts. The marketing division of popcorn.org unleashes an aggressive campaign designed to get Americans to consume even more popcorn. (a) Determine the null and a
> A can of soda is labeled as containing 12 fluid ounces. The quality control manager wants to verify that the filling machine is neither over-filling nor under-filling the cans. (a) Determine the null and alternative hypotheses that would be used to deter
> A(n)_____sample is obtained by dividing the population into groups and selecting all individuals from within a random sample of the groups.
> Assessed value of a house
> For the hypotheses in Problem 16, the null hypothesis is not rejected.
> For the hypotheses in Problem 14, the null hypothesis is rejected.
> For the hypotheses in Problem 13, the null hypothesis is not rejected.
> For the hypotheses in Problem 20, the null hypothesis is not rejected.
> For the hypotheses in Problem 19, the null hypothesis is rejected.
> For the hypotheses in Problem 18, the null hypothesis is not rejected.
> For the hypotheses in Problem 17, the null hypothesis is not rejected.
> For the hypotheses in Problem 16, the null hypothesis is rejected.
> For the hypotheses in Problem 15, the null hypothesis is not rejected.
> Why are convenience samples ill advised?
> For the hypotheses in Problem 14, the null hypothesis is not rejected.
> For the hypotheses in Problem 13, the null hypothesis is rejected.
> In 2017, the standard deviation of SAT score on the Evidence-based Reading and Writing Test for all students taking the exam was 100. A teacher believes that, due to changes to high school curricula, the standard deviation of SAT score has decreased.
> According to the CTIA–The Wireless Association, the mean monthly revenue per cell phone was $38.66 in 2017. A researcher suspects the mean monthly revenue per cell phone is different today.
> According to the Centers for Disease Control and Prevention, 19.6% of children aged 6 to 11 years are overweight. A school nurse thinks that the percentage of 6- to 11-year-olds who are overweight is different in her school district.
> The standard deviation in the pressure required to open a certain valve is known to be = 0.7 psi. Due to changes in the manufacturing process, the quality-control manager feels that the pressure variability has been reduced.
> Federal law requires that a jar of peanut butter that is labeled as containing 32 ounces must contain at least 32 ounces. A consumer advocate feels that a certain peanut butter manufacturer is shorting customers by underfilling the jars.
> According to the National Association of Home Builders, the mean price of an existing single-family home in 2018 was $395,000. A real estate broker believes that existing home prices in her neighborhood are lower.
> Historically, the time to order and deliver a pizza at Jimbo’s pizza was 48 minutes. Jim, the owner, implements a new system for ordering and delivering pizzas that he believes will reduce the time required to get a pizza to his customers.
> H0: = 7.8 H1: ≠ 7.8
> Which sampling method does not require a frame?
> H0: = 120 H1: < 120
> H0: p = 0.76 H1: p > 0.76
> H0: = 4.2 H1: ≠ 4.2
> H0: p = 0.2 H1: p < 0.2
> H0: = 5 H1: > 5
> True or False: Sample evidence can prove a null hypothesis is true.
> The______ is the probability of making a Type I error.
> If we do not reject the null hypothesis when the statement in the alternative hypothesis is true, we have made a Type____ error.
> What requirements must be satisfied in order to construct a confidence interval about a population proportion?
> For what type of variable does it makes sense to construct a confidence interval about a population mean?
> Describe a circumstance in which stratified sampling would be an appropriate sampling method.
> For what type of variable does it make sense to construct a confidence interval about a population proportion?
> Does chewing your food for a longer period of time reduce one’s caloric intake of food at dinner? A researcher requires a sample of 75 healthy males to chew their food twice as long as they normally do. The researcher then records the calorie consumption
> A researcher wanted to know whether consumption of green tea on a daily basis reduces LDL (bad) cholesterol. She obtains a random sample of 500 subjects. Each subject consumes at least 1 cup of green tea daily for 1 year. After 1 year, the researcher det
> Researchers at the Gallup Organization asked a random sample of 1016 adult Americans aged 21 years or older, “Right now, do you think the state of moral values in the country as a whole is getting better, or getting worse?”
> A developmental mathematics instructor wishes to estimate the typical amount of time students dedicate to studying mathematics in a week. She asks a random sample of 50 students enrolled in developmental mathematics at her school to report the amount of
> Researchers conducted a study to see the effect of specific lifestyle and dietary changes for preventing long-term weight gain. The study involved the consolidation of three cohorts from the Nurses’ Health Study (NHS): (1) cohort of 121,701 female regist
> Go to www.pearsonhighered.com/ sullivanstats to obtain the data file 9_4_21. The data represent the status of licenses for short-term rentals in New Orleans, where “Yes” indicates the license is expired and “No” indicates the license is not expired. Sour
> The following data represent the property tax for a random sample of 50 single-family homes in the city of Houston. Suppose you want to estimate the typical property real estate tax for a single-family home in the city of Houston. (a) What type of variab
> Sleep apnea is a disorder in which you have one or more pauses in breathing or shallow breaths while you sleep. In a cross-sectional study of 320 individuals who suffer from sleep apnea, it was found that 192 had gum disease. Note: In the general populat
> Harris Interactive conducted a poll of a random sample of 2234 adult Americans 18 years of age or older and asked, “Which is more annoying to you, tailgaters or slow drivers who stay in the passing lane?” Among those surveyed, 1184 were more annoyed by t
> Research the sampling methods used by a market research firm in your neighborhood. Report your findings to the class. The report should include the types of sampling methods used, number of stages, and sample size.
> Clayton Kershaw of the Los Angeles Dodgers is one of the premier pitchers in baseball. His most popular pitch is a four-seam fastball. The data below represent the pitch speed (in miles per hour) for a random sample of 18 of his four-seam fastball pitche
> In a random sample of 40 visitors to a certain theme park, it was determined that the mean amount of money spent per person at the park (including ticket price) was $93.43 per day with a standard deviation of $15. Construct and interpret a 99% confidence
> In a survey of 1008 adult Americans, the Gallup organization asked, “When you retire, do you think you will have enough money to live comfortably or not?” Of the 1008 surveyed, 526 stated that they were worried about having enough money to live comfortab
> Fifty rounds of a new type of ammunition were fired from a test weapon, and the muzzle velocity of the projectile was measured. The sample had a mean muzzle velocity of 863 meters per second and a standard deviation of 2.7 meters per second. Construct an
> In a random sample of 100 estate tax returns that was audited by the Internal Revenue Service, it was determined that the mean amount of additional tax owed was $3421 with a standard deviation of $2583. Construct and interpret a 90% confidence interval f
> Based on a poll conducted by the Centers for Disease Control, 862 of 1013 randomly selected adults said that they always wear seat belts. Construct and interpret a 95% confidence interval for the proportion of adults who always wear seat belts.
> Self-driving vehicles periodically suffer from a disengagement of the self-driving feature. In these cases, it is important to know how long it takes for the driver to manually take control of the vehicle. In a study of 487 instances where a self-driving
> A simple random sample of size n = 210 is drawn from a population. The sample mean is found to be / = 20.1, and the sample standard deviation is found to be s = 3.2. Construct a 90% confidence interval for the population mean
> A simple random sample of size n = 40 is drawn from a population. The sample mean is found to be / = 120.5, and the sample standard deviation is found to be s = 12.9. Construct a 99% confidence interval for the population mean.
