Question

The probability of someone buying a particular newspaper in a town is 0.4. Out of 80 customers who come into a shop, what is the probability of at most 26 customers buy this newspaper? Use the normal distribution to approximate the binomial distribution.

Answer 1

Solution :

Using binomial distribution,

= n * p = 80 * 0.4 = 32

= n * p * q = 80 * 0.4 * 0.6 = 4.38178

Using continuity correction ,

= P((x - ) / (26.5 - 32) / 4.38178)

= P(z -1.255)

= 0.1047

Probability = 0.1047