Question

A transect is an archaeological study area that is 1/5 mile wide and 1 mile long. A site in a transect is the location of a significant archaeological find. Let x represent the number of sites per transect. In a section of Chaco Canyon, a large number of transects showed that x has a population variance σ² = 42.3. In a different section of Chaco Canyon, a random sample of 25 transects gave a sample variance s² = 46.7 for the number of sites per transect. Use a 5% level of significance to test the claim that the variance in the new section is greater than 42.3. Find a 95% confidence interval for the population variance.

Find the value of the chi-square statistic for the sample. (Round your answer to two decimal places.)


What are the degrees of freedom?

Find the requested confidence interval for the population variance. (Round your answers to two decimal places.)

lower limit
upper limit

Answer 1

The statistical software output for this problem is:

Hence,

Chi - square statistic = 26.49

Degrees of freedom = 24

Confidence interval:

Lower limit = 28.47

Upper limit = 90.38