Questions from Business Statistics

Q: In 2016, the Graduate Management Admission Council reported that the variance

In 2016, the Graduate Management Admission Council reported that the variance in GMAT scores was 14,660. At a recent summit, a group of economics professors met to discuss the GMAT performance of unde...

Q: Magazine Subscribers. A Fortune study found that the variance in the

Magazine Subscribers. A Fortune study found that the variance in the number of vehicles owned or leased by subscribers to Fortune magazine is .94. Assume a sample of 12 subscribers to another magazine...

Q: Refer to the Scheer Industries example in Section 8.2.

Refer to the Scheer Industries example in Section 8.2. Use 6.84 days as a planning value for the population standard deviation. a. Assuming 95% confidence, what sample size would be required to obtain...

Q: Find the following F distribution values from Table 4 of Appendix B

Find the following F distribution values from Table 4 of Appendix B. a. F.05 with degrees of freedom 5 and 10 b. F.025 with degrees of freedom 20 and 15 c. F.01 with degrees of freedom 8 and 12 d. F.1...

Q: A sample of 16 items from population 1 has a sample variance

A sample of 16 items from population 1 has a sample variance s12 = 5.8 and a sample of 21 items from population 2 has a sample variance s22 = 2.4. Test the following hypotheses at the .05 level of sig...

Q: Consider the following hypothesis test. H0: σ21 = σ22

Consider the following hypothesis test. H0: σ21 = σ22 Ha: σ21 ≠ σ22 a. What is your conclusion if n1 = 21, s21= 8.2, n2 = 26, and s22 = 4.0? Use α = .05 and the p-value approach. b. Repeat the test us...

Q: Investors commonly use the standard deviation of the monthly percentage return for

Investors commonly use the standard deviation of the monthly percentage return for a mutual fund as a measure of the risk for the fund; in such cases, a fund that has a larger standard deviation is co...

Q: In its 2016 Auto Reliability Survey, Consumer Reports asked subscribers to

In its 2016 Auto Reliability Survey, Consumer Reports asked subscribers to report their maintenance and repair costs. Most individuals are aware of the fact that the average annual repair cost for an...

Q: Barron’s has collected data on the top 1000 financial advisers. Merrill

Barron’s has collected data on the top 1000 financial advisers. Merrill Lynch and Morgan Stanley have many of their advisers on this list. A sample of 16 of the Merrill Lynch advisers and 10 of the Mo...

Q: The variance in a production process is an important measure of the

The variance in a production process is an important measure of the quality of the process. A large variance often signals an opportunity for improvement in the process by finding ways to reduce the p...