Find the standard deviation of sample data summarized in a frequency distribution table by using the vormula below, were x represents the class midpoint and f represents the class frequency.
s= square root n[sum(f X x^2)] - [sum(f X x)]^2 divided by n(n-1) standard deviation for frequency distribution.
Daily low temp (f) 30-34 35-39 30-44 45-49 50-54 55-59
Frequency 1 5 10 8 5 1
round to once decimal as needed
Book answer is 5.8 degrees F