The director of a daycare center noticed that the infants were getting more diaper rashes than usual in the summer time. The policy of the center was to change the diapers on a schedule every three hours. The director wanted to find out if adjusting the diaper-changing schedule to every two hours would significantly reduce the number of diaper rashes. Since some of the infants seemed to have more sensitive skin, she decided to directly compare the number of diaper rashes for each individual infant when the diaper was changed every three hours versus every two hours. For the first week, the daycare center changed the diapers as usual every three hours and noted the number of days that each infant had symptoms of a diaper rash. During the second week, the teachers changed diapers every two hours and recorded the number of days with symptoms of a diaper rash. At the end of the two weeks, they compared for each individual infant the number of days with symptoms of a diaper rash when the diapers were changed every three hours versus every two hours.

The following hypotheses were tested:

H0: μd = 0

Ha: μd > 0

The following is the (edited) output for the test:

Which of the following is an appropriate conclusion based on the output?

A. The data provide sufficient evidence to reject H0 and, thus, conclude that the mean number of days with diaper rash symptoms when changed every three hours is higher than the mean number of days with diaper rash symptoms when changed every two hours.

B. The data provide sufficient evidence to reject H0. We therefore conclude the data do not provide evidence to conclude that the mean number of days with diaper rash symptoms when changed every three hours is higher than the mean number of days with diaper rash symptoms when changed every two hours.

C. The data do not provide sufficient evidence to reject H0. We therefore conclude that the mean number of days with diaper rash symptoms when changed every three hours is higher than the mean number of days with diaper rash symptoms when changed every two hours.

D. The data do not provide sufficient evidence to reject H0. In other words, based on the data we cannot conclude that the mean number of days with diaper rash symptoms when changed every three hours is higher than the mean number of days with diaper rash symptoms when changed every two hours.