These data are obtained on the random variable X the cpu tim

These data are obtained on the random variable X, the cpu time (in seconds) required to run a program using a statistical package: summation x = 127 and summation x^2 = 722,92. Find the median, sample mean, variance and standard deviation. Can we say that the shape of the distribution of the values approximately symmetric? Why?

Solution

Mean = 127/25 = 5.08

Variance = 722.92/25 - 5.08^2

= 3.1104

Std dev = 1.7636

Median is the middle entry when arranged in ascending order

= 4.9

As mean and median do not vary much we can assume it is nearly symmetrical