Questions from Business Statistics

Q: A survey of your customers shows, to your surprise, that

A survey of your customers shows, to your surprise, that 42 out of 200 randomly selected customers were not satisfied with after-sale support and service. a. Find the summary statistics: the sample si...

Q: A sample of 93 coils of sheet steel showed that the average

A sample of 93 coils of sheet steel showed that the average length was 101.37 m, with a standard deviation of 2.67 m. a. Interpret the standard deviation in words; in particular, what is it measuring...

Q: As a basis for a brochure describing the speed of a new

As a basis for a brochure describing the speed of a new computer system, you have measured how long it takes the machine to complete a particular benchmark database program. Since the state of the dis...

Q: Samples of rock taken from various places in a proposed mine have

Samples of rock taken from various places in a proposed mine have been analyzed. For each sample, a “rate of return” number has been computed that represents the profit obtained (by selling the refine...

Q: You are concerned about waste in the newspaper publishing process. Previously

You are concerned about waste in the newspaper publishing process. Previously, no measurements were made, although it is clear that frequent mistakes often require many pounds of newsprint to be throw...

Q: So far at your new job, you have landed nine sales

So far at your new job, you have landed nine sales contracts with an average price of $3,782 and a standard deviation of $1,290. a. Identify a reasonable idealized population that this sample represen...

Q: Do you agree that drawing a second sample was a good idea

Do you agree that drawing a second sample was a good idea?

Q: A random sample of 50 recent patient records at a clinic shows

A random sample of 50 recent patient records at a clinic shows that the average billing per visit was $53.01 and the standard deviation was $16.48. a. Find the 95% confidence interval for the mean and...

Q: Consider the quality scores measured for a random sample of agricultural produce

Consider the quality scores measured for a random sample of agricultural produce: 16:7,17:9,23:5,13:8,15:9,15:2,12:9,15:7 a. Find the 95% confidence interval for the population mean quality. b. Find t...

Q: To help your restaurant marketing campaign target the right age levels,

To help your restaurant marketing campaign target the right age levels, you want to find out if there is a statistically significant difference, on the average, between the age of your customers and t...