Math 220 : Elementary Statistics Kane Nashimoto
Exam 1 - Ch. 1, 2, 3, 4
Spring 2006 Name :
Directions: This exam contains six problems worth a total of 100 points. For each computa-
tional problem, you must first write the formula to be used and present all your subsequent
work in order to receive full or partial credit. Circle your final answers.
1. The each of the following, determine whether the data are discrete or continuous.
(4 pts. ea.)
(a) Numbers of door dents for a sample of 20 cars . . . . .
(b) Hourly wages (in dollars) for part-time jobs . . . . . . . .
(c) Lengths (in centimeters) of five lizards . . . . . . . . . . . . .
(d) Precipitations (in millimeters) for 30 cities . . . . . . . . .
2. For an intermediate calculus course, the scores on the final exam had a mean of 64.8
with a standard deviation of 12.3. The median score was 68.0.
(a) What do the relative locations of the mean and median tell you about the skew-
ness of the distribution of the exam scores? (8 pts.)
(b) Compute the z-score for a student whose exam score was 60. (8 pts.)
3. Refer to Problem 2. The instructor of the course felt that the scores were lower than
anticipated. Thus, the instructor decided to apply a “curve” by adding 10 points
to every student. No substantial computation is necessary to answer the following
questions.
(a) What would the value of the mean score be after applying the curve? (8 pts.)
(b) What would the value of the standard deviation be after applying the curve?
(8 pts.)
1
