Question

(3 marks)

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A group of pupils scored an average of 92 marks for a test. The boys scored an average of 90 marks while the girls
scored an average of 95 marks. What is the ratio of the number of boys to the number of girls in the group?​

Answer 1

Answer: 1.5 : 1

Step-by-step explanation:

The average of 92 marks for the test is a weighted average of the proportion of students in the class.

Assume boys are in the proportion, x.

(90 * x) + (95 * (1 - x)) = 92

90x + 95 - 95x = 92

-5x = 92 - 95

-5x = -3

x = -3/-5

x = 0.6

Boys are 0.6 of the class

Girls are:

= 1 - 0.6

= 0.4

0.6 : 0.4

1.5 : 1