Question

The mean number of hours worked for the 30 males was 6, and for the 20 females was 9. The overall mean number of hours worked is, A. Cannot be determined. B. 7.2 hours C. 7.5 hours D. 6.5 hours

Answer 1

B

Explanation:

The overall mean number of hours worked can be determined by calculating the weighted average of the means for males and females, taking into account the sample size as weights.

Given:

X₁ = 6 (mean number of hours worked for males)

X₂ = 9 (mean number of hours worked for females)

n₁ = 30 (sample size for males)

n₂ = 20 (sample size for females)

The overall mean number of hours worked, denoted as X, can be calculated as follows:

X = (X₁ * n₁ + X₂ * n₂) / (n₁ + n₂)

Plugging in the given values:

X = (6 * 30 + 9 * 20) / (30 + 20)

X = (180 + 180) / 50

X = 360 / 50

X = 7.2