The Manager of a toy company claims that the variance of the assembly time for all workers is 28 square minuted.

The Manager of a toy company claims that the variance of the assembly time for all workers is 28 square minuted. A sample of 10 workers was taken, and the assembly time for one toy for each worker under normal conditions was recorder. This information produced a sample variance of 24 square minutes. Construct a 99% confidence interval for the variance and teh standard deviation of assembly times for all workers.