Computer & Data AnalysisDr. Samir Safi – Mr. Ibrahim Abed
Laboratory Midterm Exam - 1
oct.24, 2013
Student’s Name:
Student ID #:
Note the variable name is shown in the square brackets []
Question #1: (8 Points)
Open the file Student, then answer the following questions
1. (5 points) Generate side-by-side histogram of the distribution of heights[ht],
separating men and women [gender]
2. (3 points) Find the mean and median amount paid for a haircut [haircut]. Comment on the
comparison of the mean and median.
Question #2: (12 Points)
Open the file Bodyfat, then answer the following questions
1. (4 points) Which of the following variables is most closely related to bodyfat
percentage[fatper]: age[age], weight[weight], abdomen circumferences
[abdomen], or thigh circumferences [thigh]? Why might this be?
1
2. (3 points)With the full dataset, construct a 95% confidence interval estimate
for the body density [density]. What does this interval tell us?
3. (3 points) Do the same for the first 100 observations?
4. (2 points) Comment on the comparison of the two intervals you've just
constructed. Suggest real-world reasons which might underline the
comparisons?
Good luck
2