Answer:
The appropriate way to label the age intervals on the x-axis is: Option: B
B) 7−10; 11−14; 15−18; 19−22
Explanation:
The rule for determining the number of intervals is:
- Take the square root of the number of observations to the nearest whole number.
Here we have 13 observations
and √(13)=3.6055≈4
Hence, we have a total of four intervals.
The width of each interval is calculated as:
- The ratio of range to the total number of intervals.
i.e. (22-7)/4=15/4=3.75≈4
We know that for classifying a class interval in a histogram the width of each of the interval must be equal.
A) 7−11; 11−14; 15−19; 20−22
In option: A--
the width of first interval is: 4
width of second interval is: 3
Width of third interval is: 4
Width of fourth interval is: 2
Hence, the width of each interval is not equal.
Hence, option: A is discarded.
C) 7−10; 10−15; 15−19; 19−22
In option: C--
the width of first interval is: 3
width of second interval is: 5
Width of third interval is: 4
Width of fourth interval is: 3
Hence, the width of each interval is not equal.
Hence, option: C is discarded.
D) 7−13; 15−19; 20−22
In option: D--
the width of first interval is: 6
width of second interval is: 4
Width of third interval is: 2
Hence, the width of each interval is not equal.
Hence, option: D is discarded.
B) 7−10; 11−14; 15−18; 19−22
There are a total of 4 intervals and also width of each interval is equal and equal to 4.
Hence, option: B is the correct answer.