Question

Mrs. Greenback a financial analyst hired an advertising agency to advertise her mutual funds to the public. Before she hired the advertising agency, she received on average (mean) 200 calls from new investors per week (50 weeks), with a standard deviation of 16 calls per week. Mrs. Greenback would like to investigate whether there has been an overall change in the number of calls received weekly after she hired the advertising agency. After she hired the advertising agency, she started to receive 206 calls per week (50 weeks). To put it another way, did the mean number of inquiries per week differ significantly from 200 calls per week after she hired the advertising agency?

What is your decision at 0.01 significance level?

Grupo de opciones de respuesta

Reject the null hypothesis (Ho) and conclude that the advertising agency did increase the mean number of calls at 0.01 significance level.

Do not reject the alternative hypothesis (H1) as the advertising agency did not increase the mean number of calls at 0.01 significance level.

Do not reject the null hypothesis (Ho) as the advertising agency did not increase the mean number of calls at 0.01 significance level.

Reject the alternative hypothesis (H1) as the advertising agency did increase the mean number of calls at 0.01 significance level.

Answer 1

Given that

number of weeks =n=50

sample mean =m=206

population SD=SD=16

we have to test that

now test statistics is given by

now P-Value =P(Z>2.652) =0.004

since P-value is less than level of significance hence we reject H0 that is we have enough evidence to support the claim that there is increase in the number of calls from 200.

Hence correct option is

Reject the null hypothesis (Ho) and conclude that the advertising agency did increase the mean number of calls at 0.01 significance level.