Statistics and Probability Answers

Suppose that the operation manager of computer package delivery service is contemplating the purchase of a new fleet of trucks. When packages are efficiently stored in the trucks in preparation for delivery, two major constraints have to be considered. The weight in pounds and volume in cubic feet for each item. Now suppose that in a sample of 200 packages the average weight is 26.0pounds with a standard deviation of 3.9 pounds. In addition suppose that the average volume for each of these packages is 8.8 cubic feet with standard deviation of 2.2 cubic feet. How can we compare the variation of the weight and volume?

In an Ergonomics lab activity, specifically that for memory recall, 12 students were given ten minutes to try to memorize a list of 20 nonsense words. Each student was then asked to list as many of the words he or she could remember both one hour and twenty-four hours later. The number of words recalled correctly for each student is shown below:
Student A B C D E F G H I J K L
1-hour later 14 9 18 12 13 17 16 16 19 8 15 7
24-hours later 10 6 14 6 8 10 12 10 14 5 10 5
Determine, at the 95% confidence level, that for all such students, the mean number of words recalled after one hour exceeds that recalled after twenty-four hours by 5 words.

The article “Statistical Evidence of Discimination” (J. Amer. Stat. Assoc., 1982: 773- 783) discusses the court case Swain v. Alabama (1965), in which it was alleged that there was discrimination against blacks in grand jury selection. Census data suggested that 25% of those eligible for grand jury service were black, yet a random sample of 1050 called to appear for possible duty yielded only 177 blacks. Using a level 0.01 test, does this data argue strongly for a conclusion of discrimination?

Statistics and Probability
Question #117532
Suppose that the operation manager of package delivery service is contemplating the purchase of a new fleet of trucks. When packages are efficiently stored in the trucks in preparation for delivery, two major constraints have to be considered. The weight in pounds and volume in cubic feet for each item. Now suppose that in a sample of 200 packages the average weight is 26.0pounds with a standard deviation of 3.9 pounds. In addition suppose that the average volume for each of these packages is 8.8 cubic feet with standard deviation of 2.2 cubic feet. How can we compare the variation of the weight and volume?

The operations manager of a package delivery service is contemplating the purchase of a new fleet of trucks. When packages are efficiently stored in the truck for delivery, there are two major constraints that have to be considered, the weight in pounds and the volume in cubic feet for each item. Management takes a sample of 200 packages. The average weight is 26.0 pounds with a standard deviation of 3.9 pounds. The average volume of each package is 8.8 cubic feet with a standard deviation of 2.2 cubic feet. Management is concerned with the variability of both the weight and volume. Prove statistically whether the weight or the volume has the greater variability

A dart hits the square dartboard shown below at a random point. Find the probability that the dart lands in the shaded circular region. Each side of the dartboard is 13in , and the radius of the shaded region is 5 in.
use the value 3.14 for pi

Suppose that the operation manager of package delivery service is contemplating the purchase of a new fleet of trucks. When packages are efficiently stored in the trucks in preparation for delivery, two major constraints have to be considered. The weight in pounds and volume in cubic feet for each item. Now suppose that in a sample of 200 packages the average weight is 26.0pounds with a standard deviation of 3.9 pounds. In addition suppose that the average volume for each of these packages is 8.8 cubic feet with standard deviation of 2.2 cubic feet. How can we compare the variation of the weight and volume?

Two types of chemical solutions treams, A and B, were tested for their alkalinity levels. Analysis of the 6 samples taken from solution A showed that the mean alkalinity level is 7.52 with a standard deviation of 0.024 while the 5 samples taken at Solution B showed an alkalinity level of 7.49 with a standard deviation of 0.032. Using a (a) 0.05 and (b) 0.01 significance level, determine whether the streams have different alkalinity levels. Use F-distribution.

The standard deviation of the annual precipitations of a region over a period of 100 years was 16 cm. During the last 15 years a standard deviation of annual precipitations was computed as 10 cm. Test the hypothesis that the precipitations in the region have become less variable than in the past, using a significance level of (a) 0.05 and (b) 0.01. Use chi-square distribution

The Research & Development (R&D) team of a manufacturing firm discovered a new procedure that can be introduced into the production process that can substantially decrease production time. The firm has a limited fund allocated for process modifications that a standard is set for acceptability, that only a production time decrease of at least 8% is acceptable. Six production trials were undertaken showing a mean production time decrease of 8.4% with a standard deviation of 0.32%. Using a level of significance of (a) 0.01 and (b) 0.05, test the hypothesis that the process should be introduced. Use t-distribution