1-20chapter stats

A random sample of 9 days for the city of acorn

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: for both samples in minutes are given below. The distribution of repair times for both brand A and brand B is highly skewed. On the average, can it be concluded that the repair time for brand A is significantly higher than the repair time for brand B? Test at α = .05. A. Reject the null hypothesis B. Fail to reject the null hypothesis 1-1782 Chapter 01 - An Introduction to Business Statistics 72. A cholesterol test was given to 10 heart patients with high cholesterol levels. The same 10 heart patients are then given a new cholesterol-reducing drug for six months. Before the patients begin taking the drug, they are told to maintain their current diets and eating habits so that the effect of the drug can be more effectively determined. After taking the drug for six months, the same patients are given a cholesterol test again. The pharmaceutical company that manufactures the drug wants to determine if the drug is helpful in reducing cholesterol levels. Distribution of cholesterol level is not normally distributed. State the alternative hypothesis for this problem. A. The probability distribution of cholesterol readings of patients before and after taking the drug for six months is identical. B. The probability distribution of cholesterol readings of patients before taking the drug has shifted to the right of the probability distribution of cholesterol readings of patients after taking the drug. C. The probability distribution of cholesterol readings of patients before taking the drug has shifted to the left of the probability distribution of cholesterol readings of patients after taking the drug. D. The probability distribution of cholesterol readings of patients before taking the drug has shifted to the right or left of the probability distribution of cholesterol readings of patients after taking the drug. 1-1783 Chapter 01 - An Introduction to Business Statistics 73. A cholesterol test was given to 10 heart patients with high cholesterol levels. The same 10 heart patients are then given a new cholesterol-reducing drug for six months. Before the patients begin taking the drug, they are told to maintain their current diets and eating habits so that the effect of the drug can be more effectively determined. After taking the drug for six months, the same patients are given a cholesterol test again. The cholesterol levels before and after taking the drug is given below. Distribution of cholesterol level is not normally distributed. At α = .05, test to determine if the drug is helpful in reducing cholesterol levels. A. Reject the null hypothesis B. Fail to reject the null hypothesis 74. Two NFL scouts are in the process of recruiting 7 college senior football players (receivers). After a careful review and evaluation, both scouts ranked the seven receivers in terms of their professional career prospects. If we want to determine whether the two scouts have similar opinions about the professional football career prospects of the seven players, state the null and alternative hypothesis. A. H0: ρs ≠ 0 B. H0: ρs ≥ 0 C. H0: ρs ≤ 0 D. H0: ρs = 0 1-1784 Chapter 01 - An Introduction to Business Statistics 75. Two NFL scouts are in the process of recruiting 7 college senior football players (receivers). After a careful review and evaluation, both scouts ranked the seven receivers in terms of their professional career prospects. The rankings are given below. At = .05, does it appear that the two scouts have similar opinions about the professional football career prospects of the seven players? A. Reject the null hypothesis B. Fail to reject the null hypothesis 76. In a manufacturing facility producing fasteners, a foreman suspects that the diameter of the bolt produced by his first shift workers is greater than the diameter of the bolts produced by his second shift workers. He takes a sample of 5 bolts from the first shift and a sample of 4 bolts from the second shift and measures the diameters in inches. Below are the results from 5 first shift and 4 second shift observations. Distribution of bolt diameter measurements is not normally distributed. At = .05, can we conclude that his suspicion is correct? A. Reject the null hypothesis, diameter is greater for 1st shift versus 2nd shift B. Fail to reject the null hypothesis, no evidence that the diameters differ by shift 1-1785 Chapter 01 - An Introduction to Business Statistics 77. Three years ago, a major hotel chain purchased a large number of heating and airconditioning units from three major manufacturers, A, B and C. The accounting department of the hotel chain kept records on their repair and replacement costs over the last 3 years. The manager of the purchasing department randomly selected 6 brand A, 7 brand B, and 6 brand C heating and air-conditioning unit records. The repair and replacement costs in dollars are summarized in the following table. At = .05, can it be concluded that there is a significant difference in repair costs among the three brands? A. Reject the null hypothes...
View Full Document

Ask a homework question - tutors are online