5. The board of directors for Procter and Gamble is concerned that only 19.5% of the people who use toothpaste buy Crest toothpaste. A marketing director suggests that the company invest in a new marketing campaign which will include advertisements and new labeling for the toothpaste. The research department conducts product trials in test markets for one month to determine if the market share increases with new labels.

a.Write the company’s null and alternative hypotheses

b.In this context describe a Type I error and the impact such an error would have on the company.

c.In this context, describe a Type II error and the impact such an error would have on the company.

6 answers

Take a shot. What do you think.
A sample has M = 72 and s = 4. In this sample, what is the X value corresponding to z = –2.00?
Substitute the values given if you are expected to solve for x in this formula:
z = (x - mean)/sd -->sd = standard deviation.

-2.00 = (x - 72)/4

Solve for x.
Here's a few hints:

Null hypothesis:
Population proportion is equal to some value.
Alternative hypothesis:
Population proportion is greater than some value. (The problem is asking if the market share increases.)

Type I errors result when you reject the null and it's true. Type II errors result when you accept the null and it's false.

See if you can go from here.
A sample has M=72 and s=4. In this sample, what is the X value corresponding to

z = -2?
is the answerposted for this?