Question

50 students each did a mathematics test. the mean score for these 50 students was 8.4. there were 30 boys. the mean score for these bots were 8.25. workout the mean score for the girls.

Answer 1

[(30 x 8,25) + (20 x n)] / 50 = 8,4

247,5 + 20 x n = 420

n = (420 - 247,5) : 20

n = 8,625