Dr Patton is a professor of English Recently she counted the

Dr. Patton is a professor of English. Recently she counted the number of misspelled words in a group of student essays. She noted the distribution of misspelled words per essay followed the normal distribution with a population standard deviation of 2.44 words per essay. For her 10am section of 40 students, the mean number of misspelled words was 6.05. Construct a 95% confidence interval for the mean number of misspelled words in the population of student essays.

HOW DO I DO THIS IN EXCEL?

Solution

E = 1.96*2.44/sqrt40 = 0.7562 CI = (6.05-E,6.05+E) CI = (5.29384,6.8062)