The following data from a random sample represents the average daily energy intake in kJ for each of eleven healthy women:

52605470564061806390651568057515751582308770

Interest centred on comparing these data with an underlying mean daily energy intake of 7725 kJ This was the recommended daily intake. Departures from this mean in either direction were considered to be of interest. Assuming that the population is normal and the population variance is unknown. An appropriate two-tailed hypothesis test at the 5% level of significance was conducted. The null hypothesis is H0: m = 7725.

(a) What is the value of observed test statistics?

(b) What is the degree of freedom df in this problem?

(c) In order to make a decision as to whether to accept or reject the null hypothesis, we need to compare the observed test statistic with the critical value. What is this critical value |ta/2| ?

(d)What conclusions can be drawn, at the 5% level of significance?