D Question 15 1 pts A random sample of 100 exam scores is taken from the normally distributed population with unknown mean and a populations standard deviation know and equal to 3. The sample mean score is 68. Find a 90% confidence interval estimate for the population mean of exam scores. Please round to the nearest hundredths and write your answer in the form ( , ); for example (31,34) or (25,46). Do not type in any extra spaces. (notice that the only difference between this question and EXERCISE 1 is the change in the sample size - it was increased; is the new confidence interval narrower or wider?)