If a fair coin is tossed25

times, the probability distribution forthenumber ofheads,X

, is given below. Find the mean and the standard deviation of the probability distribution using Excel.

• Enter the mean and round thestandard deviation to two decimal places.

x P(x)

0 0

1 0

2 0

3 0.0001

4 0.0004

5 0.0016

6 0.0053

7 0.0143

8 0.0322

9 0.0609

10 0.0974

11 0.1328

12 0.155

13 0.155

14 0.1328

15 0.0974

16 0.0609

17 0.0322

18 0.0143

19 0.0053

20 0.0016

21 0.0004

22 0.0001

23 0

24 0

25 0