The heights (in cm) of 40 students of a class were recorded. The sum of the heights was found to be 6690cm and the sum of the squares of the heights was 1128050cm2.
a. (i) Find the mean height of the students.
b. (ii) Compute the variance and the standard deviation of the heights, correct to one decimal place.
c. (iii) Comment briefly on the amount of dispersion indicated by the standard deviation in relation to the mean height.