Business Statistics

Chapter 9 | Statistical Inference: Estimation for Single Populations 303

1. A researcher has selected a random sample of size 50 from a

population; sample mean is obtained as 25 and sample standard

deviation is obtained as 3.68. Construct a 95% condence inter-

val to estimate population mean.

2. In a small town, a research company wants to estimate the aver-

age amount spent by families on groceries. From a random sam-

ple of 150 families, sample mean and sample standard deviation

were obtained as Rs 900 and Rs 125, respectively. Construct a

90% condence interval to estimate population mean.

3. A random sample of size 80 is taken ...