The sandwich chain was embarrassed to find out that the mean length of a foot long sandwich is less than a foot They made some changes and asked you to repeat your study with a random sample of 40 sandwiches The mean for this The 99 new random sample is 12 08 with a standard deviation of 0 2 The 95 confidence interval is confidence interval is Confidence Level as a percent 95 interval is 12 02 to 12 14 99 interval is 12 00 to 12 16 O95 interval is 12 00 to 12 16 99 interval is 12 02 to 12 14 O95 interval is 12 03 to 12 13 99 interval is 12 00 to 12 16 95 interval is 12 02 to 12 14 99 interval is 12 03 to 12 13 90 95 99 z value 1 645 1 960 2 576