A student is making independent random guesses on a test. The probability the student guess correctly...

A student is making independent random guesses on a test. The probability the student guess correctly is 0.5 for each question. Assume that the guesses are independent. Find the probability of 13 or more correct in 20 guesses. Round your answer to 3 decimal places.

Expert Solution

Ler X be the number of correct answers.

Then X~Binomial(20,0.5)

X	P(X=x)
0	0.00000095367
1	0.00001907349
2	0.00018119812
3	0.00108718872
4	0.00462055206
5	0.01478576660
6	0.03696441650
7	0.07392883301
8	0.12013435364
9	0.16017913818
10	0.17619705200
11	0.16017913818
12	0.12013435364
13	0.07392883301
14	0.03696441650
15	0.01478576660
16	0.00462055206
17	0.00108718872
18	0.00018119812
19	0.00001907349
20	0.00000095367

We need to find

We get that

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orchestra answered 2 years ago

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