The mean score of a random sample of 17 students in Canduman National High School who took a special test in Statistics and Probability is 83.5. The standard deviation of the scores is 4, and the...

The mean score of a random sample of 17 students in Canduman National High School who took a special test in Statistics and Probability is 83.5. The standard deviation of the scores is 4, and the sample size comes from approximately normal population.

a) What is the t-value in solving for the population mean given the confidence interval of 90%?

b) What does this t-value mean under t-distribution?