On one of my homework assignments I had this question:

A coin is tossed 72 times. Find the standard deviation for the number of heads that will be tossed.

Could you please help me get started? Then I will be fine.

Thank you,
Cheryl
:confused:

Quote:

---

Originally Posted by cspearson

on one of my homework assignments I had this question:

A coin is tossed 72 times. Find the standard deviation for the number of heads that will be tossed.

Could you please help me get started? Then I will be fine.

Thank you,
Cheryl
:confused:

---

Does your textbook specify a formula for the standard deviation of a binomial distribution?

If not, it's been a very long time since I took probability and statistics, but I believe the standard deviation is np(1-p), where n is the number of trials and p is the probability of success.

This is a binomial event. The standard deviation is sqrt(npq), where n = # of tosses, p = probability of getting a head on any one toss and q = probability of getting a tail on any one toss.