In a data distribution, the first quartile, the median and the means are 30.8, 48.5 and 42.0 respectively. If the coefficient skewness is , use the information to answer

questions 9 and 10.

9. What is the approximate value of the third quartile

(Q3 ), correct to 2 decimal places?

​

--- The third quartile

-- Variance

Step-by-step explanation:

Given

-- First quartile

--- Median

--- Mean

--- Coefficient of skewness

Solving (9): The third quartile

This is calculated from

So, we have:

Cross Multiply

Open bracket

Collect like terms

Divide both sides -1.38

--- approximated

Solving (b): The variance

First, calculate the standard deviation from:

So:

Make SD the subject

So, the variance is: