Q: The Virginia Cooperative Extension reports that the mean weight of yearling Angus
The Virginia Cooperative Extension reports that the mean weight of yearling Angus steers is 1152 pounds. Suppose that weights of all such animals can be described by a Normal model with a standard dev...
See AnswerQ: In Exercise 5 you were asked whether you thought the differences in
In Exercise 5 you were asked whether you thought the differences in political identification across diet preferences were real. To examine that question further, we randomly scrambled the students pol...
See AnswerQ: Based on the Normal model N(100,15) describing
Based on the Normal model N(100,15) describing IQ scores, what percent of people IQs would you expect to be 1. over 80? 2. under 90? 3. between 112 and 132?
See AnswerQ: The Mathematics section of the ACT test had a mean of 20
The Mathematics section of the ACT test had a mean of 20.9 and an SD of 5.3 for the years 2013 2015. If these are well modeled by a Normal distribution, about what percent of students scored 1. over 3...
See AnswerQ: The mean household income in the U.S. in 2014
The mean household income in the U.S. in 2014 was about $72,641 and the standard deviation was about $85,000. (The median income was $51,939.) If we used the Normal model for these incomes, 1. What wo...
See AnswerQ: Corey has 4929 songs in his computer music library. The lengths
Corey has 4929 songs in his computer music library. The lengths of the songs have a mean of 242.4 seconds and standard deviation of 114.51 seconds. A Normal probability plot of the song lengths looks...
See AnswerQ: The histogram shows the distribution of mean ACT composite scores for all
The histogram shows the distribution of mean ACT composite scores for all Wisconsin public schools in 2015. 80.1% of the data points fall between one standard deviation below the mean and one standard...
See AnswerQ: People with z-scores above 2.5 on an IQ
People with z-scores above 2.5 on an IQ test are sometimes classified as geniuses. If IQ scores have a mean of 100 and a standard deviation of 15 points, what IQ score do you need to be considered a g...
See AnswerQ: A town January high temperatures average 36 with a standard deviation of
A town January high temperatures average 36 with a standard deviation of 10, while in July the mean high temperature is 74 and the standard deviation is 8. In which month is it more unusual to have a...
See AnswerQ: An incoming freshman took her college placement exams in French and mathematics
An incoming freshman took her college placement exams in French and mathematics. In French, she scored 82 and in math 86. The overall results on the French exam had a mean of 72 and a standard deviati...
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