Question

The following chart represents the height of boys and girls in a class. Which of the following is true about the given data?


\begin{tabular}{|c|c|} \hline Height of boys (in ft) & Height of girls (in ft) \\ \hline \( 4.2 \) & \( 4.1 \) \\ \hline \( 3.5 \) & \( 3.8 \) \\ \hline \( 4.9 \) & \( 3.5 \) \\ \hline \( 4.8 \) & \( 3.5 \) \\ \hline \( 4.2 \) & \( 3.6 \) \\ \hline \end{tabular}

• A. Average height of girls is greater than average height of boys.
• B. Average height of boys and girls are same.
• C. Average height of boys is greater than average height of girls.
• D. Average height of boys = 4.9 ft

Answer 1

The correct option is C Average height of boys is greater than average height of girls.

The given data is


Let us find the median of the two data sets.

The first data set is (Boys):

4.2, 3.5, 4.9, 4.8, 4.2

The mean of the data set is the sum of the data divided by the number of data values

Mean = $\frac{sumofalldata}{numberofdata}$

= $\frac{4.2+3.5+4.9+4.8+4.2}{5}$

= $\frac{21.6}{5}$ = 4.32

Hence, average height of boys = 4.32 ft


The next data set (Girls) is :

4.1, 3.8, 3.5, 3.5, 3.6

Mean = $\frac{sumofalldata}{numberofdata}$

= $\frac{4.1+3.8+3.5+3.5+3.6}{5}$

= $\frac{18.5}{5}$

= 3.7

Hence, average height of girls = 3.7 ft

The first option is "Average height of boys = 4.2ft"

This is not true, since the average height of boys = 4.32 ft


The next option is "Average height of boys and girls are same."

This is not true, since the average height of boys and girls are not same.

The next option is "Average height of boys is greater than girls"

Average height of boys is 4.32 ft and girls is 3.7 ft.

Hence, the option "Average height of boys is greater than girls" is true.

The next option is "Average height of girls is greater than average height of boys", which is incorrect.