The chassis assembly time for a television set is observed for two operators. A random sample...

The chassis assembly time for a television set is observed for two operators. A random sample of 12 assemblies from the first operator gives an average assembly time of 22 minutes with a standard deviation of 3.5 minutes. A random sample of 10 assemblies from the second operator gives an average assembly time of 20.3 minutes with a standard deviation of 2.2 minutes.

a. Find a 90% confidence interval for the ratio of the variances of the operators' assembly times.

b.Find a 95% confidence interval for the ratio of the variances of the operators' assembly times.

c. Can we conclude that the variance of time for the second operator is less is than the first one? Use a level of significance alpha of 0.01.

Please show work and explain. Thanks.

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