In: Statistics and Probability
1- The number of calories in a hamburger depends on what ingredients are included. The following are determinations of calorific values of a sample of homemade large hamburgers:
350 375 400 356 378 379 340 320 330 324 360 390
Assume that the calorific values for the hamburgers are normally distributed.
a) Find the standard error of the sample mean.
b) Obtain the 95% confidence intervals for the mean calorific values of the burgers.
2- The following show the number of hours a sample of High school students from a local high school studied a week:
21, 15, 18, 24, 15, 18, 20, 23, 24, 12, 10, 20, 12, 18, 20, 14, 17
Assume that the weekly study hours are normally distributed.
a) find the 90% confidence intervals for the mean number of study hours.
b) find the margin of error for the 95% confidence interval of the mean number of study hours for all students in this high school. The margin of error equals half length of the confidence interval.