Hood Projects is a fullservice interactive agency that offer

Hood Projects is a full-service interactive agency that offers companies a variety of website services. In the past, the average sales amount for a client had been $ 126,05. Hood recently redesigned a client company\'s website and wants to show that sales have increased. An analyst select 38 sales records at random from the client\'s 2000 access logs and she finds a mean of $129.54 with a standard deviation of $ 10.20. What is the standard error of the mean? What is the null hypothesis? State the alternative hypothesis; is the alternative one-or two-sided? What is the value of the t statistic? What is the P-value of the test statistic? Construct a confidence interval for a = .05. Using the confidence interval, state your conclusion.

Solution

1)

standard error = 10.20/38 = 0.2684

2)

null hypothesis :

Ho: u > 126.05

3)

alternate hypothesis :

Ha: u <=126.05

4)

tstatistic

= 129.54 - 126.05 / 0.2684

= 13.0029