I have submitted this question two times and still am not getting the correct an
ID: 2923616 • Letter: I
Question
I have submitted this question two times and still am not getting the correct answer and not seeing where I am getting it wrong.
Professor Notes: I would use the binomial cumulative density function built into your calculator. He is making 30 trials and if he has no ESP, his probability of getting any one trial correct is 0.5. So you want to compute P(x>=26) = 1 - P(x<=25) = 1 - binomcdf(30,0.5,25).
A man claims to have extrasensory perception (ESP). As a test, a fair coin is flipped 3030 times, and the man is asked to predict the outcome in advance. He gets 2626 out of 3030 correct. What is the probability that he would have done at least this well if he had no ESP?
Probability =
Explanation / Answer
pcap = x/n = 26/30 = .87
p0 = .50
z = (p0-pcap)/sqrt(p0*p0'/n) = (.87-.50)/sqrt(.87*.13/50) = 7.78
P(z>7.78) = ~0
Which means that the probability of getting atleast 26 right is too less. i.e. almost 0