Question

It is known that a certain hockey goalie will successfully make a save 85.39% of the time. Suppose that the hockey goalie attempts to make 15 saves. What is the probability that the hockey goalie will make at least 13 saves?

  

Let XX be the random variable which denotes the number of saves that are made by the hockey goalie. Find the expected value and standard deviation of the random variable.

  E(X)=E(X)=
   σ=

Answer 1

The probability that the hockey goalie will make at least 13 saves = 0.62128

E(X)= 12.809
   σ= 1.368

	15	n
	0.8539	p
		cumulative
X	P(X)	probability
0	0.00000	0.00000
1	0.00000	0.00000
2	0.00000	0.00000
3	0.00000	0.00000
4	0.00000	0.00000
5	0.00001	0.00001
6	0.00006	0.00007
7	0.00044	0.00051
8	0.00258	0.00309
9	0.01175	0.01484
10	0.04120	0.05604
11	0.10945	0.16549
12	0.21323	0.37872
13	0.28759	0.66631
14	0.24013	0.90644
15	0.09356	1.00000
	1.00000
	12.809	expected value
	1.871	variance
	1.368	standard deviation