In assessing the normality of data, why is a normal probability plot especially advantageous for small samples?
What will be an ideal response?
Q. 2The scores from a state standardized test have a bell-shaped distribution with a mean of 100 and a standard deviation of 15. Use the Empirical Rule to find the percentage of students with scores between 70 and 130.
A) 95 B) 100 C) 99.7 D) 68
Q. 3For the following conditions, determine if it is appropriate to use the normal distribution to approximate a binomial distribution with n = 37 and p = 0.7.
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Q. 4A congressman wants to measure the level of support in his district for campaign finance reform and wants to determine whether there is a gender gap with respect to this issue.
One researcher suggests that they find separate confidence intervals for the percent of men and the percent of women who favor reform and then see if the intervals overlap. Another researcher suggests that they find a confidence interval for the difference in the proportions of men and women who favor reform. Which is the correct approach? Why?
Q. 5In assessing the normality of a data set, why is it easier to interpret a normal probability plot than it is to interpret a histogram?
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Q. 6A severe drought affected several western states for 3 years. A Christmas tree farmer is worried about the drought's effect on the size of his trees.
To decide whether the growth of the trees has been retarded, the farmer decides to take a sample of the heights of 25 trees. Typically trees of this age have a mean height of 65 inches with a standard deviation of 9 inches. Assuming the distribution is bell shaped, where do you expect middle 95 of the tree heights to fall?
A) between 47 and 83 inches tall B) over 56 inches tall
C) between 38 and 92 inches tall D) between 56 and 74 inches tall
Q. 7For the following conditions, determine if it is appropriate to use the normal distribution to approximate a binomial distribution with n = 9 and p = 0.1.
What will be an ideal response?
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