Introductory Statistics (10th Edition)
10th Edition
ISBN: 9780321989178
Author: Neil A. Weiss
Publisher: PEARSON
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Chapter 6.4, Problem 124E
In each of Exercises 6.121–6.126, we have provided a normal
6.124
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A researcher believes that the so-called “sugar high” is not real. He gathered 30 adolescents and recorded their activity level in the scale of 0 – 100 (0 = not active and 100 = super active). First, he recorded participants’ activity level before they consumed candy. After recording their pre-sugar activity level, the researcher gave out 5 Snickers bars to participants. Then, he recorded their post-sugar activity level. The average difference between post-sugar and pre-sugar activity level is 50 (i.e., the activity levels are higher after sugar than prior to it) with a standard deviation of 10.
A). Complete test statistic and critical values
B). Conclusion
A researcher believes that the so-called “sugar high” is not real. He gathered 30 adolescents and recorded their activity level in the scale of 0 – 100 (0 = not active and 100 = super active). First, he recorded participants’ activity level before they consumed candy. After recording their pre-sugar activity level, the researcher gave out 5 Snickers bars to participants. Then, he recorded their post-sugar activity level. The average difference between post-sugar and pre-sugar activity level is 50 (i.e., the activity levels are higher after sugar than prior to it) with a standard deviation of 10.
A). What is the type of test you will use? (z-test, single-sample t-test, paired-samples t-test, or independent samples t-test) and why (what information provided in the problem)B). What are the hypotheses (Be Specific)
Heart rate during laughter. Laughter is often called “the best medicine,” since studies have shown that laughter can reduce muscle tension and increase oxygenation of the blood. In the International Journal of Obesity (Jan. 2007), researchers at Vanderbilt University investigated the physiological changes that accompany laughter. Ninety subjects (18–34 years old) watched film clips designed to evoke laughter. During the laughing period, the researchers measured the heart rate (beats per minute) of each subject,
with the following summary results:
Mean = 73.5,
Standard Deviation = 6. n=90 (we can treat this as a large sample and use z)
It is well known that the mean resting heart rate of adults is 71 beats per minute. Based on the research on laughter and heart rate, we would expect subjects to have a higher heart beat rate while laughing.Construct 95% Confidence interval using z value. What is the lower bound of CI?
a) Calculate the value of the test statistic.(z*)
b) If…
Chapter 6 Solutions
Introductory Statistics (10th Edition)
Ch. 6.1 - What is a density curve?Ch. 6.1 - State the two basic properties of every density...Ch. 6.1 - For a variable with a density curve, what is the...Ch. 6.1 - In each of Exercises 6.46.11, assume that the...Ch. 6.1 - In each of Exercises 6.46.11, assume that the...Ch. 6.1 - In each of Exercises 6.46.11, assume that the...Ch. 6.1 - In each of Exercises 6.46.11, assume that the...Ch. 6.1 - In each of Exercises 6.46.11, assume that the...Ch. 6.1 - In each of Exercises 6.46.11, assume that the...Ch. 6.1 - In each of Exercises 6.46.11, assume that the...
Ch. 6.1 - In each of Exercises 6.46.11, assume that the...Ch. 6.1 - A curve has area 0.425 to the left of 4 and area...Ch. 6.1 - A curve has area 0.613 to the left of 65 and area...Ch. 6.1 - Prob. 14ECh. 6.1 - A variable is approximately normally distributed....Ch. 6.1 - Precisely what is meant by the statement that a...Ch. 6.1 - Two normally distributed variables have the same...Ch. 6.1 - Which normal distribution has a wider spread: the...Ch. 6.1 - Consider two normal distributions, one with mean 4...Ch. 6.1 - Prob. 20ECh. 6.1 - True or false: The mean of a normal distribution...Ch. 6.1 - Prob. 22ECh. 6.1 - Sketch the normal distribution with a. = 3 and =...Ch. 6.1 - Prob. 24ECh. 6.1 - For a normally distributed variable, what is the...Ch. 6.1 - Prob. 26ECh. 6.1 - Prob. 27ECh. 6.1 - The area under a particular normal curve between...Ch. 6.1 - A variable has the density curve whose equation is...Ch. 6.1 - A variable has the density curve whose equation is...Ch. 6.1 - Waiting for the Train. A commuter train arrives...Ch. 6.1 - Bacteria on a Petri Dish. A petri dish is a small,...Ch. 6.1 - Fire Loss. The loss, in millions of dollars, due...Ch. 6.1 - Emergency Room Traffic. Desert Samaritan Hospital...Ch. 6.1 - Female College Students. Refer to Example 6.3 on...Ch. 6.1 - Female College Students. Refer to Example 6.3 on...Ch. 6.1 - Giant Tarantulas. One of the larger species of...Ch. 6.1 - Serum Cholesterol Levels. According to the...Ch. 6.1 - New York City 10-km Run. As reported in Runners...Ch. 6.1 - Prob. 40ECh. 6.1 - Ages of Mothers. From the document National Vital...Ch. 6.1 - Prob. 42ECh. 6.1 - Cloudiness in Breslau. In the paper Cloudiness:...Ch. 6.1 - Prob. 44ECh. 6.1 - Prob. 45ECh. 6.1 - Prob. 46ECh. 6.1 - Chips Ahoy! 1,000 Chips Challenge. Students in an...Ch. 6.1 - Gestation Periods of Humans. Refer to the...Ch. 6.1 - Delaying Adulthood. In the paper, Delayed...Ch. 6.2 - With which normal distribution is the standard...Ch. 6.2 - Without consulting Table II, explain why the area...Ch. 6.2 - Prob. 52ECh. 6.2 - Prob. 53ECh. 6.2 - Prob. 54ECh. 6.2 - Prob. 55ECh. 6.2 - Prob. 56ECh. 6.2 - Prob. 57ECh. 6.2 - Prob. 58ECh. 6.2 - Use Table II to obtain the areas under the...Ch. 6.2 - Use Table II to obtain the areas under the...Ch. 6.2 - Use Table II to obtain the areas under the...Ch. 6.2 - Use Table II to obtain the areas under the...Ch. 6.2 - Use Table II to obtain the areas under the...Ch. 6.2 - Use Table II to obtain the areas under the...Ch. 6.2 - Use Table II to obtain the areas under the...Ch. 6.2 - Use Table II to obtain the areas under the...Ch. 6.2 - Use Table II to obtain each shaded area under the...Ch. 6.2 - Use Table II to obtain each shaded area under the...Ch. 6.2 - In each part, find the area under the standard...Ch. 6.2 - The total area under the following standard normal...Ch. 6.2 - In Exercises 6.716.82, use Table II to obtain the...Ch. 6.2 - In Exercises 6.716.82, use Table II to obtain the...Ch. 6.2 - In Exercises 6.716.82, use Table II to obtain the...Ch. 6.2 - Prob. 74ECh. 6.2 - In Exercises 6.716.82, use Table II to obtain the...Ch. 6.2 - In Exercises 6.716.82, use Table II to obtain the...Ch. 6.2 - Prob. 77ECh. 6.2 - In Exercises 6.716.82, use Table II to obtain the...Ch. 6.2 - Prob. 79ECh. 6.2 - Prob. 80ECh. 6.2 - In Exercises 6.716.82, use Table II to obtain the...Ch. 6.2 - In Exercises 6.716.82, use Table II to obtain the...Ch. 6.2 - Complete the following table.Ch. 6.2 - Prob. 84ECh. 6.2 - Prob. 85ECh. 6.3 - Briefly, for a normally distributed variable, how...Ch. 6.3 - Explain why the percentage of all possible...Ch. 6.3 - Prob. 88ECh. 6.3 - Prob. 89ECh. 6.3 - A variable is normally distributed with mean 68...Ch. 6.3 - A variable is normally distributed with mean 10...Ch. 6.3 - Prob. 92ECh. 6.3 - A variable is normally distributed with mean 6 and...Ch. 6.3 - A variable is normally distributed with mean 68...Ch. 6.3 - A variable is normally distributed with mean 10...Ch. 6.3 - A variable is normally distributed with mean 0 and...Ch. 6.3 - Giant Tarantulas. One of the larger species of...Ch. 6.3 - Serum Cholesterol Levels. According to the...Ch. 6.3 - New York City 10-km Run. As reported in Runners...Ch. 6.3 - Green Sea Urchins. From the paper Effects of...Ch. 6.3 - Arterial Cord pH. Umbilical cord blood analysis...Ch. 6.3 - Elephant Pregnancies. G. Wittemeyer et al. studied...Ch. 6.3 - Gibbon Song Duration. A preliminary behavioral...Ch. 6.3 - Friendship Motivation. In the article Assessing...Ch. 6.3 - Brain Weights. In 1905, R. Pearl published the...Ch. 6.3 - Children Watching TV. The A. C. Nielsen Company...Ch. 6.3 - Heights of Female Students. Refer to Example 6.3...Ch. 6.3 - Womens Shoes. Research reveals that foot length of...Ch. 6.3 - College-Math Success. Researchers S. Lesik and M....Ch. 6.3 - Tipping. In the article Are Christian/Religious...Ch. 6.3 - Booted Eagles. The rare booted eagle of western...Ch. 6.3 - Emergency Room Traffic. Desert Samaritan Hospital...Ch. 6.3 - Let 0 1. For a normally distributed variable,...Ch. 6.3 - Express the quartiles, Q1, Q2, and Q3, of a...Ch. 6.3 - Express the kth percentile, Pk , of a normally...Ch. 6.4 - Under what circumstances is using a normal...Ch. 6.4 - Explain why assessing the normality of a variable...Ch. 6.4 - Explain in detail what a normal probability plot...Ch. 6.4 - How is a normal probability plot used to detect...Ch. 6.4 - Explain how to obtain normal scores from Table III...Ch. 6.4 - In each of Exercises 6.1216.126, we have provided...Ch. 6.4 - In each of Exercises 6.1216.126, we have provided...Ch. 6.4 - In each of Exercises 6.1216.126, we have provided...Ch. 6.4 - In each of Exercises 6.1216.126, we have provided...Ch. 6.4 - In each of Exercises 6.1216.126, we have provided...Ch. 6.4 - Prob. 126ECh. 6.4 - In Exercises 6.1276.130, a. use Table III in...Ch. 6.4 - Prob. 128ECh. 6.4 - In Exercises 6.1276.130, a. use Table III in...Ch. 6.4 - In Exercises 6.1276.130, a. use Table III in...Ch. 6.4 - Prob. 131ECh. 6.4 - In Exercises 6.1316.134, a. obtain a normal...Ch. 6.4 - Prob. 133ECh. 6.4 - Prob. 134ECh. 6.4 - Body Temperature. A study by researchers at the...Ch. 6.4 - Vegetarians and Omnivores. Philosophical and...Ch. 6.4 - Prob. 137ECh. 6.4 - Finger Length of Criminals. In 1902, W. R....Ch. 6.4 - Prob. 139ECh. 6.4 - Emergency Room Traffic. Desert Samaritan Hospital...Ch. 6.5 - Why should you sometimes use normal-curve areas to...Ch. 6.5 - The rule of thumb for using the normal...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - Prob. 157ECh. 6.5 - Prob. 158ECh. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - In Exercises 6.1436.160, X denotes a binomial...Ch. 6.5 - TrueFalse Exams. Refer to Example 6.20 on page...Ch. 6.5 - Prob. 162ECh. 6.5 - TrueFalse Exams. If, in Example 6.20, the...Ch. 6.5 - TrueFalse Exams. If, in Example 6.20, the...Ch. 6.5 - Applying the Concepts and Skills In Exercises...Ch. 6.5 - In Exercises 6.1656.172, apply Procedure 6.3 on...Ch. 6.5 - In Exercises 6.1656.172, apply Procedure 6.3 on...Ch. 6.5 - In Exercises 6.1656.172, apply Procedure 6.3 on...Ch. 6.5 - In Exercises 6.1656.172, apply Procedure 6.3 on...Ch. 6.5 - In Exercises 6.1656.172, apply Procedure 6.3 on...Ch. 6.5 - In Exercises 6.1656.172, apply Procedure 6.3 on...Ch. 6.5 - Prob. 172ECh. 6.5 - Roulette. An American roulette wheel consists of...Ch. 6.5 - Flashlight Battery Lifetimes. A brand of...Ch. 6.5 - Prob. 175ECh. 6 - What is a density curve, and why are such curves...Ch. 6 - In each of Problems 24, assume that the variable...Ch. 6 - In each of Problems 24, assume that the variable...Ch. 6 - In each of Problems 24, assume that the variable...Ch. 6 - Prob. 5RPCh. 6 - State two of the main reasons for studying the...Ch. 6 - Prob. 7RPCh. 6 - Answer true or false to each statement. Give...Ch. 6 - Explain the relationship between percentages for a...Ch. 6 - Prob. 10RPCh. 6 - Prob. 11RPCh. 6 - Prob. 12RPCh. 6 - What key fact permits you to determine percentages...Ch. 6 - Prob. 14RPCh. 6 - Prob. 15RPCh. 6 - Prob. 16RPCh. 6 - State the empirical rule for variables.Ch. 6 - Prob. 18RPCh. 6 - Prob. 19RPCh. 6 - Prob. 20RPCh. 6 - Prob. 21RPCh. 6 - Prob. 22RPCh. 6 - For the standard normal curve, find the z-score(s)...Ch. 6 - Dispensing Coffee. A coffee machine is supposed to...Ch. 6 - Forearm Length. In 1903, K. Pearson and A. Lee...Ch. 6 - Birth Weights. The WONDER database, maintained by...Ch. 6 - Lower Limb Surgery. The study Intrathecal...Ch. 6 - Verbal GRE Scores. The Graduate Record Examination...Ch. 6 - Verbal GRE Scores. Refer to Problem 28, and fill...Ch. 6 - Prob. 30RPCh. 6 - Prob. 31RPCh. 6 - Diarrhea Vaccine. Acute rotavirus diarrhea is the...Ch. 6 - FOCUSING ON DATA ANALYSIS UWEC UNDERGRADUATES...Ch. 6 - CASE STUDY DISCUSSION CHEST SIZES OF SCOTTISH...
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- Q1arrow_forwardBighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 13.8 19.3 14.4 19.6 20.0 Σx = 15; Σy = 87.1; Σx2 = 55; Σy2 = 1554.45; Σxy = 274b) Find the equation of the least-squares line. (Round your answers to two decimal places.) ŷ = + x (c) Find r. Find the coefficient of determination r2. (Round your answers to three decimal places.) r = r2 = d) Test the claim that the population correlation coefficient is positive at the 1% level of significance. (Round your test statistic to three decimal places.) t =arrow_forwardBighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 15.8 17.3 14.4 19.6 20.0 Σx = 15; Σy = 87.1; Σx2 = 55; Σy2 = 1,540.45; Σxy = 272 (a) Find x, y, b, and the equation of the least-squares line. (Round your answers for x and y to two decimal places. Round your least-squares estimates to three decimal places.) x = y = b = ŷ = + xarrow_forward
- Bighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 15.8 17.3 14.4 19.6 20.0 Σx = 15; Σy = 87.1; Σx2 = 55; Σy2 = 1,540.45; Σxy = 272 (a) Find x, y, b, and the equation of the least-squares line. (Round your answers for x and y to two decimal places. Round your least-squares estimates to three decimal places.) x = y = b = ŷ = + x (b) Draw a scatter diagram for the data. Plot the least-squares line on your scatter diagram. (c) Find the sample correlation coefficient r and the coefficient of determination r2. (Round your answers to three decimal places.) r = r2 = What percentage of variation in y is…arrow_forwardplease solve parts d e farrow_forwardBighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 12.2 17.5 14.4 19.6 20.0 (c) Find the sample correlation coefficient r and the coefficient of determination r2. (Round your answers to three decimal places.) r = ? r2 = ? What percentage of variation in y is explained by the least-squares model? __________ %(Round your answer to one decimal place.) incorrect answers: I submitted this question and was told this is the answer but it is NOT CORRECT. please help !! r=0.800 r2= 0.640 64% ( above answers are incorrect)arrow_forward
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