Math 533 64541  Mathematics homework help
1. (TCO A) Consider the following sample data on the age of the 30 employees that were laid off recently from DVC Inc.
21 38 20 26 37 52 37 24 45 20
50 49 44 30 29 42 56 46 60 30
32 25 47 55 38 25 20 29 32 30
a. Compute the mean, median, mode, and standard deviation, Q1, Q3, Min, and Max for the above sample data on age of employees being laid off.
b. In the context of this situation, interpret the Median, Q1, and Q3. (Points : 33)
2. (TCO B) Consider the following data on newly hired employees in relation to which part of the country they were born and their highest degree attained.

HS 
BS 
MS 
PHD 
Total 
East 
3 
5 
2 
1 
11 
Midwest 
7 
9 
2 
0 
18 
South 
5 
8 
6 
2 
21 
West 
1 
7 
8 
6 
22 
Total 
16 
29 
18 
9 
72 
If you choose one person at random, then find the probability that the person
a. is from the Midwest.
b. is from the South and has a PHD.
c. is from the West, given that person only holds a MS degree. (Points : 18)
3. (TCO B) A source in the Internal Revenue Service has stated that historically 90% of federal tax returns filed are free of arithmetic errors. A random sample of 25 returns are selected and checked carefully for arithmetic errors. Assuming independence, find the probability that
a. all 25 returns are free of arithmetic errors.
b. at most 23 returns are free of arithmetic errors.
c. more than 17 are free of arithmetic errors. (Points : 18)
4. (TCO B) The Bank of Connecticut issues Visa and Mastercard credit cards. The balances on these credit cards follow a normal distribution with a mean of $845 and standard deviation of $270.
a. What percentage of balances is below $1,200?
b. What percentage of balances is between $600 and $1,000?
c. Find the 12th percentile for balance (i.e., find the cutoff for the lowest 12% of balances). (Points : 18)
Question 5.
6. (TCO C) The personnel manager of a large firm wants to find the percentage of employee absences that occur on Fridays. A random selection of 500 employee absences is taken from work records over the past several years. The data reveals that 220 of the 500 employee absences were on Fridays.
8. (TCO D) Engineering studies show that it is feasible to install a windmill for generating electrical power if the mean wind speed is greater than 14 mi per hour (mph). The Piedmont Electric Coop is considering locating mulls at the top of Mount Hunter. A random sample of 45 wind speed readings yields the following results.
Sample Size = 45 Sample Mean = 14.9 mph Sample Standard Deviation = 3.8 mph Does the sample data provide sufficient evidence to conclude that installation is feasible at this location (using a = .10)? Use the hypothesis testing procedure outlined below. a. Formulate the null and alternative hypotheses. b. State the level of significance. c. Find the critical value (or values), and clearly show the rejection and nonrejection regions. d. Compute the test statistic. e. Decide whether you can reject Ho and accept Ha or not. f. Explain and interpret your conclusion in part e. What does this mean? g. Determine the observed pvalue for the hypothesis test and interpret this value. What does this mean? h. Does the sample data provide sufficient evidence to conclude that installation is feasible at this location (using a = .10)? (Points : 24) 1. (TCO E) McCave Development Enterprises is considering whether to build a shopping mall in Statesville. The manager wants you to analyze the relationship between mall size and the rate of return on invested capital. You select a random sample of 16 cities similar to Statesville in demographic and economic characteristics and collect the following data on FOOTAGE (in 10,000 square feet) and RETURN (rate of return as a %).
1. (TCO E) An insurance firm wishes to study the relationship between driving experience (X1, in years), number of driving violations in the past three years (X2), and current monthly auto insurance premium (Y). A sample of 12 insured drivers is selected at random. The data is given below (in MINITAB):
