Business Statistics

Chapter 9 | Statistical Inference: Estimation for Single Populations 295

(b) For x = 50, number of trials = 175, construct 95% con-

dence interval

(c) For x = 50, number of trials =175, construct 99% con-

dence interval

9C3. In India the informal (non-organized) market share for

voltage stabilizers is 80%.

4

A researcher believes that this

market share may have changed. For verifying his belief,

the researcher has taken a random sample of size 80 volt-

age stabilizer customers. Out of 80 customers, 55 customers

have purchased from the informal market. Construct a 95%

condence interval to estimate the proportion ...