Answer:
a) The third quartile Q₃ = 56.45
b) Variance

Explanation:
Given that :
= 30.8
Median
= 48.5
Mean = 42
a) The mean is less than median; thus the expression showing the coefficient of skewness is given by the formula :




Divide both sides by 1.38

b) The objective here is to determine the approximate value of the variance;
Using the relation






Variance =

