Question

EXA 9-10B A semiconductor manufacturer produces controllers used in automobile engine applications, The customers require that the error in estimating the true proportion of defective items must be less than 0.04. From a previous survey, the estimate is 0.06. How large a sample is required? Ans: 136 EXA 9-10B A semiconductor manufacturer produces controllers used in automobile engine applications. The customers require that the error in estimating the true proportion of defective items must be less than 0.03. From a previous survey, the estimate is 0.01. How large a sample is required?

Answer 1

(1)

Sample Size (n) is given by:

za/2 xp x (1 – p)

Take $\alpha$ = 0.05

From Table, critical values of Z = $\pm$ 1.96

Given:

p = 0.06

e = 0.04

Substituting, we get:

n = 1.962 x 0.06 x (1 -0.06) · = 136 0.042

So,

Answer is:

136

(2)

Sample Size (n) is given by:

za/2 xp x (1 – p)

Take $\alpha$ = 0.05

From Table, critical values of Z = $\pm$ 1.96

Given:

p = 0.01

e = 0.03

Substituting, we get:

m = 1,962 x 0.01 x (1 - 0,01) 0,032 = 43

So,

Answer is:

43