Lenovo Group Limited a Hong Kong IT company has a 30 share o

Lenovo Group Limited, a Hong Kong IT company, has a 30% share of the Hong Kong PC market. Suppose 10 new PC buyers are selected at random from the Hong Kong population. What is the probability that fewer than 3 bought their PC from Lenovo?

A) 0.028 B) 0.121 C) 0.233 D) 0.267 E) 0.382

Solution

Probabiity of buying it from Lenovo is 0.3

We will use Biomial distribution here to answer this question

Pr(x<3) Means Probability that fewer than 3

Pr(x<3)=10C3(0.3)^3(0.7)^7=(120*0.027*(0.7)^7=0.2668

Answer is 0.267