Business Statistics

Chapter 8 | Sampling and Sampling Distributions 279

1. A population has mean 40 and standard deviation 10. A random

sample of size 50 is taken from the population, what is the prob-

ability that the sample mean is each of the following:

(a) Greater than or equal to 42

(b) Less than 41

(c) Between 38 and 43

2. A housing board colony of Gwalior consists of 2000 houses. A

researcher wants to know the average income of the households

in this housing board colony. The mean income per household is

Rs 150,000 with standard deviation Rs 15,000. A random sam-

ple of 200 households is selected by a researcher and analysed.

What is the ...