For the data of Problem 9·24, determine the dispersion measures, that is, the variance, standard deviation and coefficient of variation·
Problem 9.24
The following concrete strength data (in ksi) were collected using an ultrasonic nondestructive testing method at different locations of an existing structure: 3·5, 3·2, 3·1, 3·5, 3·6, 3·2, 3·4, 2·9, 4·1, 2·6, 3·3, 3·5, 3·9, 3·8, 3·7, 3·4, 3·6, 3·5, 3·5, 3·7, 3·6, 3·8, 3·2, 3·4, 4·2, 3·6, 3·1, 2·9, 2·5, 3·5, 3·4, 3·2, 3·7, 3·8, 3·4, 3·6, 3·5, 3·2, 3·6, and 3·8· Plot a histogram and a frequency diagram for concrete strength·