Question

Find standard deviation .
size= 5-10, 10-15, 15-20, 20-25 ,25-30, 30-35 ,35-40.
f= 5, 8, 12, 17, 12, 8, 5​

Answer 1

standard deviations can be find by this method

1. work out the mean
2. then for each number subtract the mean and square the results
3. then work out the mean of those squared difference
4. take the square root of that