Question

Seatbelts A histogram is to be constructed from the measured breaking points (in pounds) of tested car seatbelts. Identify two key features of a histogram of those values that would suggest that the data have a normal distribution.

Short answer

The two key features of the histogram, which are suggestive of underlying normal distribution, are

• the bell-shaped curve and
• the symmetric trait.

Step-by-step solution

Given information

A sample of seatbelts is analyzed to study the breaking point (in kilograms).

Histogram of normal distribution

The histogram of a dataset that is either obtained from the normally distributed population or has a normal distribution should have the following key features.

• The histogram should be bell-shaped. That is, the frequencies should first increase from a small value, then reach the maximum, and then gradually decrease.
• The histogram should be symmetric. That is, the two halves of the histogram should be mirror images of each other.

State the characteristics 

Here, it is given that the sample of breaking points is used to plot a histogram.

For the histogram to depict that the sample follows a normal distribution, it should be bell-shaped and symmetric.