Find the standard deviation of sample data summarized in a frequency distribution table by using the formula below, where x represents the class midpoint, f represents the class frequency, and n represents the total number of sample values. Also, compare the computed standard deviations to these standard deviations obtained by using Formula 3-4 with the original list of data values:

Pulse Rates ofFemales ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Frequency60?69..................................................1270?79..................................................1480?89..................................................1190?99....................................................1100?109...............................................1110?119...............................................0120?129................................................1

n[E(fx)] [E(f x)] s = standard deviation for frequency distribution n(n 1)