A random sample of 26 observations is used to estimate the population variance. The sample mean and sample standard deviation are calculated as 63 and 4.1, respectively. Assume that the population is normally distributed. Use Table 3.

**a.**Construct the 90% interval estimate for the population variance. **(Do not round intermediate calculations. Round your answers to 2 decimal places.)**

Confidence interval to

**b.**Construct the 95% interval estimate for the population variance. **(Do not round intermediate calculations. Round your answers to 2 decimal places.)**

Confidence interval to

**c.**Use your answers to discuss the impact of the confidence level on the width of the interval. The width of the interval increases with the confidence level.The width of the interval decreases with the confidence level.

#### Top Answer

a)since the sample comes from the normal distribution, we know that the quantity (n-1)*S 2 / σ 2 Which equals 25*4.1... View the full answer