The Sugar Producers Association wants to estimate the mean yearly sugar consumption. A sample of 16 people reveals the mean yearly consumption to be 27 kg with a sample standard deviation of 9 kg. Assume a normal population. For a 90% confidence interval, what is the critical value needed?
A) t = 1.753
B) t = 2.131
C) t = 2.947
D) z = 1.645
E) z = 1.96

Question

Quizplus · Accepted Answer

Since the population standard deviation is unknown and the sample size is small (n = 16), a t-distribution should be used. For a 90% confidence interval with 15 degrees of freedom (n-1 = 16-1 = 15), the critical value is t = 1.753.

The Sugar Producers Association Wants to Estimate the Mean Yearly