The weights of 67 randomly selected axles were found to have a variance of 3.85. Construct the 80% confidence interval for the population variance of the weights of all axles in this factory. Round your answers to two decimal places.

Step-by-step explanation:

We are given the following in the question:

Sample size, n = 67

Variance = 3.85

We have to find 80% confidence interval for the population variance of the weights.

Degree of freedom = 67 - 1 = 66

Level of significance = 0.2

Chi square critical value for lower tail =

Chi square critical value for upper tail =

80% confidence interval:

Putting values, we get,

Thus, (3.13,4.91) is the required 80% confidence interval for the population variance of the weights.

if farmer matt works for 8 hours a day, how many days will it take him to completely plant 12 rows of crops? each batch of cookies needs 3/4 cups of sugar.

step-by-step explanation: