A manufacturer of cream filled donuts collected data from its automatic filling process, the amount of cream inserted into the donuts is normally distributed.To make sure that the automatic filling process is on target, quality control inspectors take a sample of 25 donuts.The correct value of t^* to construct a 99% confidence interval for the true mean amount of cream filling is ________________________ . A)2.797 B)1.711 C)2.787 D)2.060 E)1.318

Question

Quizplus · Accepted Answer

To construct a 99% confidence interval for the mean of a normally distributed population when the sample size is 25 (which is less than 30), and assuming the population standard deviation is unknown, we use the t-distribution. The degrees of freedom (df) in this case is n - 1 = 24. Looking up the t-value for 24 degrees of freedom at a 99% confidence level, the correct value is approximately 2.797.

A Manufacturer of Cream Filled Donuts Collected Data from Its