Question

What is the value of mean for the following data.

Class interval	Frequency
$350-369$	$15$
$370-389$	$27$
$390-409$	$31$
$410-429$	$19$
$430-449$	$13$
$450-469$	$6$

• A. $400$
• B. $400.58$
• C. $394$
• D. $394.50$

Answer 1

The correct option is B $400.58$

Class Intervals	Mid-values $\left(x\right)$	Frequency $\left(f\right)$	$fx$
$350-369$	$359.5$	$15$	$5,392.5$
$370-389$	$379.5$	$27$	$10,246.5$
$390-409$	$399.5$	$31$	$12,384.5$
$410-429$	$419.5$	$19$	$7,970.5$
$430-449$	$439.5$	$13$	$5,713.5$
$450-469$	$459.5$	$6$	$2,757$
		$\sum f=111$	$\sum fx=44,464.5$

Arithmetic mean $=\frac{44,464.5}{111}=400.58$