An irate student complained. The cost of textbooks was too high. He randomly surveyed 36 other students and found that the Mean Amount of money spent for text was $ XXXXXXXXXXIs the standard deviation...

An irate student complained. The cost of textbooks was too high. He randomly surveyed 36 other students and found that the Mean Amount of money spent for text was $121.60. Is the standard deviation of the population was $6.36. Find the 90% confidence interval of the true mean