Question

A man claims to have extrasensory perception (ESP). As a test, a fair coin is flipped 2020 times, and the man is asked to predict the outcome in advance. He gets 1515 out of 2020 correct. What is the probability that he would have done at least this well if he had no ESP

Answer 1

Answer: Our required probability is 0.0207.

Step-by-step explanation:

Since we have given that

n = 20

He gets 15 out of 20 correct.

Probability of success = $\dfrac{1}{2}$

Using 'binomial distribution", we get Probability that he would have done at least this well if he had no ESP,

$P(15\leq X\leq 20)=1-P(0\leq x<15)=1-binomcdf(20,0.5,15)\\\\=1-0.9793=0.0207$

Hence, our required probability is 0.0207.