Question

finding the mean

the national average height for girls in the sixth grade is also 52 inches. find the average height of the girls in this class.

the total number of girls is
the total height of the girls is inches.
the expression to find the mean is
the average height of the girls in this class is inches.

(table: number of girls, height in inches, total height; rows: 2,51,102; 8,52,416; 0,53,0; 4,54,216; totals (empty cells))

(options for average height: 0.019, 52.4)

Explanation:

Step1: Calculate the total number of girls

Add the number of girls in each group: \(2 + 8+0 + 4=14\)

Step2: Calculate the total height of the girls

Add the total height of each group: \(102+416 + 0+216 = 734\)

Step3: Write the expression for the mean

The formula for the mean \(\bar{x}=\frac{\text{Total height}}{\text{Total number of girls}}\), so the expression is \(\frac{734}{14}\)

Step4: Calculate the mean

\(\frac{734}{14}=52.42857\cdots\approx52.4\)

Answer:

The total number of girls is \(14\).
The total height of the girls is \(734\) inches.
The expression to find the mean is \(\frac{734}{14}\).
The average height of the girls in this class is \(52.4\) inches.