Questions and Answers of Essentials Of Statistics

The Nurses’ Health Study was started in 1976 with 121,700 female registered nurses who were between the ages of 30 and 55. The subjects were surveyed in 1976 and every two years thereafter. The
In order to study the seriousness of drinking and driving, a researcher obtains records from past car crashes. Drivers are partitioned into a group that had no alcohol consumption and another group
Researchers from the National Institutes of Health want to determine the current rates of smoking among adult males and adult females. They conduct a survey of 500 adults of each gender.Indicate
Researchers at the National Cancer Institute studied meat consumption and its relationship to mortality. Approximately one-half million people were surveyed, and they were then followed for a period
Lisinipril is a drug designed to lower blood pressure. In a clinical trial of Lisinipril, blood pressure levels of subjects are measured before and after they have been treated with the drug.Identify
A clinical trial of aspirin treatments is being planned to determine whether the rate of myocardial infarctions (heart attacks) is different for men and women.Identify which of these designs is most
The numbers of the current players for the Chicago Bulls basketball team are 1, 2, 3, 5, 6, 9, 11, 13, 16, 20, 22, 26, 32, and 40. Does it make sense to calculate the average (mean) of these numbers?
Which of the following best describes the level of measurement of the data listed in Exercise 1: nominal, ordinal, interval, ratio?Exercise 1Literary Digest magazine conducted a poll for the 1936
Data Set 16 includes depths (km) of the sources of earthquakes. Are these values discrete or continuous? Data Set 16: Earthquake Measurements Fifty matched pairs of magnitude/depth measurements
Are the earthquake depths described in Exercise 3 quantitative data or categorical data?Exercise 3In a test of the Atkins weight loss program, 40 subjects using that program had a mean weight loss of
Which of the following best describes the level of measurement of the earthquake depths described in Exercise 3: nominal, ordinal, interval, ratio?Exercise 3In a test of the Atkins weight loss
True or false: If you construct a sample by selecting every sixth earthquake depth from the list given in Data Set 16, the result is a simple random sample. Data Set 16: Earthquake Measurements Fifty
In a recent Gallup poll, pollsters randomly selected adults and asked them whether they smoke. Because the subjects agreed to respond, is the sample a voluntary response sample?
In a recent Gallup poll, pollsters randomly selected adults and asked them whether they smoke. Among the adults who responded to the survey question, 21% said that they did smoke. Is that value of
True or false: If data lead to a conclusion with statistical significance, then the results also have practical significance.
Find the probability of selecting someone who does not use drugs. Does the result appear to be reasonable as an estimate of the proportion of the adult population that does not use drugs?In refer to
Based on Data Set 1 “Body Data” in Appendix B, blood platelet counts of women have a bell-shaped distribution with a mean of 255.1 and a standard deviation of 65.4. (All units are 1000 cells /
An Ohio college student died when he tried to escape from a dormitory elevator that was overloaded with 24 passengers. The elevator was rated for a maximum weight of 2500 pounds. Let’s
a. Grades (A, B, C, D, F) earned in statistics classesb. Heights of students in statistics classesc. Numbers of students in statistics classesd. Eye colors of statistics studentse. Numbers of times
There are about 11,000 births each day in the United States, and the proportion of boys born in the United States is 0.512. Assume that each day, 100 births are randomly selected and the proportion
USA Today provided results from a poll of 1000 adults who were asked to identify their favorite pie. Among the 1000 respondents, 14% chose chocolate pie, and the margin of error was given as {4
A bone mineral density test is used to identify a bone disease. The result of a bone density test is commonly measured as a z score, and the population of z scores is normally distributed with a mean
Greater than 3.00 minutesIn refer to the continuous uniform distribution depicted in Figure 6-2 and described in Example 1. Assume that a passenger is randomly selected, and find the probability that
Data Set 4 “Births” in Appendix B includes birth weights of 400 babies. If we compute the values of sample statistics from that sample, which of the following statistics are unbiased estimators
Standing eye heights of men are normally distributed with a mean of 64.3 in. and a standard deviation of 2.6 in. (based on anthropometric survey data from Gordon, Churchill, et al.).a. If an eye
Data Set 4 “Births” in Appendix B includes birth weights of 400 babies. If we compute the values of sample statistics from that sample, which of the following statistics are unbiased estimators
A geneticist is investigating the proportion of boys born in the world population. Because she is based in China, she obtains sample data from that country. Is the resulting sample proportion a good
In find the critical value Zα/2 that corresponds to the given confidence level.90%
a. If 1 adult female is randomly selected, find the probability that her pulse rate is less than 80 beats per minute.b. If 16 adult females are randomly selected, find the probability that they have
Less than 4.00 minutesIn refer to the continuous uniform distribution depicted in Figure 6-2 and described in Example 1. Assume that a passenger is randomly selected, and find the probability that
In assume that scores on a bone mineral density test are normally distributed with a mean of 0 and a standard deviation of 1.a. Identify the values of μ and σ for the standard normal
a. If 1 adult female is randomly selected, find the probability that her pulse rate is greater than 70 beats per minute.b. If 25 adult females are randomly selected, find the probability that they
In find the critical value Zα/2 that corresponds to the given confidence level.99.5%
Between 2 minutes and 3 minutesIn refer to the continuous uniform distribution depicted in Figure 6-2 and described in Example 1. Assume that a passenger is randomly selected, and find the
Between 2.5 minutes and 4.5 minutesIn refer to the continuous uniform distribution depicted in Figure 6-2 and described in Example 1. Assume that a passenger is randomly selected, and find the
With n = 20 guesses and p = 0.2 for a correct answer, find P(at least 6 correct answers).In do the following: If the requirements of np ≥ 5 and nq ≥ 5 are both satisfied, estimate the indicated
In assume that females have pulse rates that are normally distributed with a mean of 74.0 beats per minute and a standard deviation of 12.5 beats per minute (based on Data Set 1 “Body Data” in
a. If 1 adult female is randomly selected, find the probability that her pulse rate is between 78 beats per minute and 90 beats per minute.b. If 16 adult females are randomly selected, find the
Express 0.0434 < p < 0.217 in the form of p̂ + E.In express the confidence interval using the indicated format. (The confidence intervals are based on the proportions of red, orange, yellow,
Example 2 referred to an elevator with a maximum capacity of 4000 lb. When rating elevators, it is common to use a 25% safety factor, so the elevator should actually be able to carry a load
The accompanying normal quantile plot was constructed from the diastolic blood pressure levels of a sample of women. What does this graph suggest about diastolic blood pressure levels of women?In
Express 0.179 < p < 0.321 in the form of p̂ + E.In express the confidence interval using the indicated format. (The confidence intervals are based on the proportions of red, orange, yellow,
Find the probability that a male has a back-to-knee length less than 21 in.Inuse the data in the table below for sitting adult males and females (based on anthropometric survey data from Gordon,
Express the confidence interval (0.0169, 0.143) in the form of p̂ – E < p < p̂ + E.In express the confidence interval using the indicated format. (The confidence intervals are based on the
Repeat Exercise 11 using medians instead of means.Data From Exercise 11a. After identifying the 16 different possible samples, find the mean of each sample, then construct a table representing the
Express the confidence interval 0.270 ± 0.073 in the form of p̂ – E < p < p̂ + E.In express the confidence interval using the indicated format. (The confidence intervals are based on the
Find the probability that a female has a back-to-knee length greater than 24.0 in.Inuse the data in the table below for sitting adult males and females (based on anthropometric survey data from
Exercise 9 “Cookies”Data From Exercise 9The numbers of chocolate chips in Chips Ahoy (reduced fat) cookies, as listed inData Set 28 “Chocolate Chip Cookies” in Appendix B.In use the Excel, or
Repeat Exercise 11 using variances instead of means.Data from in Exercise 11a. After identifying the 16 different possible samples, find the mean of each sample, then construct a table representing
Exercise 10 “Ages of Best Actresses”Data From Exercise 10The ages of actresses at the times that they won Oscars, as listed in Data Set 14 “Oscar Winner Age” in Appendix B.In use the Excel,
For males, find P90, which is the length separating the bottom 90% from the top 10%.Inuse the data in the table below for sitting adult males and females (based on anthropometric survey data from
Exercise 11 “Garbage”Data From Exercise 11The weights (pounds) of discarded yard waste, as listed in Data Set 31 “Garbage Weight” in Appendix B.In use the Excel, or StatCrunch) or a
Based on a study by Dr. P. Sorita at Indiana University, assume that 12% of us have green eyes. In a study of 650 people, it is found that 86 of them have green eyes.a. Find the probability of at
Exercise 12 “Diet Coke”Data From Exercise 12The weights (lb) of the contents in cans of Diet Coke, as listed in Data Set 26 “Cola Weights and Volumes” in Appendix B.In use the Excel, or
Assume that cans of Coke are filled so that the actual amounts are normally distributed with a mean of 12.00 oz and a standard deviation of 0.11 oz.a. Find the probability that a single can of Coke
When Mendel conducted his famous genetics experiments with peas, one sample of offspring consisted of 929 peas, with 705 of them having red flowers. If we assume, as Mendel did, that under these
Less than -1.23In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw a
Less than –1.96In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw
The Ethan Allen tour boat capsized and sank in Lake George, New York, and 20 of the 47 passengers drowned. Based on a 1960 assumption of a mean weight of 140 lb for passengers, the boat was rated to
The following are the values of net worth (in thousands of dollars) of recent members of the executive branch of the U.S. government. Test these values for normality, then take the logarithm of
Less than 1.28In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw a
A sample of human brain volumes (cm3) is obtained from those listed in Data Set 8 “IQ and Brain Size” in Appendix B: 1027, 1029, 1034, 1070, 1079, 1079, 963, 1439.In use the given data values to
Less than 2.56In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw a
When she was 9 years of age, Emily Rosa did a science fair experiment in which she tested professional touch therapists to see if they could sense her energy field. She flipped a coin to select
Greater than 0.25In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw
The U.S. Air Force requires that pilots have heights between 64 in. and 77 in.a. Find the percentage of men meeting the height requirement.b. If the Air Force height requirements are changed to
Greater than 0.18In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw
Greater than –2.00In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
In a survey of 1002 people, 70% said that they voted in a recent presidential election (based on data from ICR Research Group). Voting records show that 61% of eligible voters actually did vote.a.
The Gulfstream 100 is an executive jet that seats six, and it has a doorway height of 51.6 in.a. What percentage of adult men can fit through the door without bending?b. Does the door design with a
Greater than –3.05In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
In a study of facial behavior, people in a control group are timed for eye contact in a 5-minute period. Their times are normally distributed with a mean of 184.0 seconds and a standard deviation of
Between 2.00 and 3.00In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
Between 1.50 and 2.50In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
Between and – 2.55 and – 2.00In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In
Between – 2.75 and – 0.75In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In
Between -2.00 and 2.00In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
Between -3.00 and 3.00In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
Find the sample size needed to estimate the percentage of California residents who are left-handed. Use a margin of error of three percentage points, and use a confidence level of 99%.a. Assume that
Between –1.00 and 5.00In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each
Between – 4.27 and 2.34In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each
Less than 4.55Between – 4.27 and 2.34In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of
Greater than – 3.75In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
In order to better plan for student resources, the chairperson of the mathematics department at Broward College wants to estimate the percentage of students who own a computer. If we want to estimate
Greater than 0In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw a
A professor gives a test and the scores are normally distributed with a mean of 60 and a standard deviation of 12. She plans to curve the scores.a. If she curves by adding 15 to each grade, what is
Less than 0In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw a
Data Set 21 “Earthquakes” in Appendix B includes the depths (km) of the sources of 600 earthquakes. Use technology for the following.a. Find the mean and standard deviation of the 600 depths.b.
1. Use the survey results to construct a 95% confidence a interval estimate of the percentage of all adults who know what Twitter is.2. Identify the margin of error for this survey.3. Explain why it
Why does the bootstrap method require sampling with replacement? What would happen if we used the methods of this section but sampled without replacement?
Repeat Exercise 7 “Freshman 15” using a confidence level of 90% for parts (a) And (b) And using 1000 bootstrap samples instead of the 10 that were given in Exercise 7.Data From Exercise
A clinical trial was conducted to test the effectiveness of the drug zopiclone for treating insomnia in older subjects. After treatment with zopiclone, 16 subjects had a mean wake time of 98.9 min
You want to estimate σ for the population of waiting times for the Space Mountain ride in Walt Disney World. You want to be 99% confident that the sample standard deviation is within 1% of σ. Find
When setting specifications of quarters to be accepted in a vending machine, you must estimate the standard deviation of the population of quarters in use. Find the minimum sample size needed to be
Data Set 1 “Body Data” in Appendix B includes weights of 153 randomly selected adult males, and those weights have a standard deviation of 17.65 kg. Because it is reasonable to assume that
In use these results from a USA Today survey in which 510 people chose to respond to this question that was posted on the USA Today website: “Should Americans replace passwords with biometric
Consider the probability distribution defined by the formula where x can be any value between 0 and 10 inclusive (not just integers).The accompanying graph of this probability distribution shows that
The largest health experiment ever conducted involved a test of the Salk vaccine designed to protect children from the devastating effects of polio. The test included 201,229 children who were given
Data Set 26 “Cola Weights and Volumes” in Appendix B includes volumes (oz) of regular Coke. Based on that data set, assume that the cans are produced so that the volumes have a standard deviation
If we are using the sample data from Exercise 1 for a t test of the claim that the population mean is greater than 90 sec, what does df denote, and what is its value?Data From Exercise 1Twelve

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