Question

for the given data, construct a frequency distribution and frequency histogram of the data using five classes. describe the shape of the histogram as symmetric, uniform, skewed left, or skewed right. data set: ages of 20 cars randomly selected in a student parking lot 12 6 4 9 11 1 7 8 9 8 9 13 5 15 7 6 8 8 2 1
a. skewed left
b. symmetric
c. skewed right
d. uniform

Explanation:

Step1: Find range

Range = Max - Min. Max = 15, Min = 1, so Range = 15 - 1=14.

Step2: Calculate class width

Class width = $\frac{Range}{Number\ of\ classes}$. Number of classes = 5, so Class width = $\frac{14}{5}=2.8\approx3$.

Step3: Define classes

Classes are: 1 - 3, 4 - 6, 7 - 9, 10 - 12, 13 - 15.

Step4: Count frequencies

For 1 - 3: 3 (1, 1, 2); for 4 - 6: 5 (4, 5, 6, 6); for 7 - 9: 9 (7, 7, 8, 8, 8, 8, 9, 9, 9); for 10 - 12: 2 (11, 12); for 13 - 15: 1 (15).

Step5: Analyze shape

The frequencies increase from the first class to the third class and then decrease. The tail is on the right - hand side. So it is skewed right.

Answer:

C. skewed right