As part of an annual plan, a research firm surveyed several communities and gathered the following data. The table shows the number of children from 98 families selected at ramdom.

Number of children

0, 1, 2, 3, 4, 5, 6

Number of families

6, 13, 20, 24, 19, 11, 5

a) calculate the standard deviation for the number of children in each family

the mean for the number of children would be 3??

how do I get the standard dev.?