Astudent takes a multiple choice test with 40 questions. the probability that a student answers a given question correctly is 0.5, independent of all other questions. the probability that the student answers more than n questions correctly is greater than 0.10. the probability that the student answers more than n+1 questions correctly is less than 0.10. calculate n using normal approximation with continuity correction. answer is 23. explain your work.

Step-by-step explanation:

X no of questions student answers is binomial with n =40 and p =0.5

If approximated to normal, X is Normal with

mean = np = 20 and variance = npq = 10

P(X>N) >0.10

We use std normal distribution table to get z value first then convert to x value

So

This is with continuity correction.

Hence without continuity correction this equals 7.2-0.5 = 6.7

x>6.7

n = 7

answer

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step-by-step explanation: