WAEC - Mathematics (1991 - No. 34)
The mean of 30 observations recorded in an experiment is 5. lf the observed largest value of 34 is deleted, find the mean of the remaining observations
5
4
3.9
3.4
3.0
Giải thích
x = 5, \(\frac{\sum {fx}}{\sum {f}}\) =
5= \(\frac{\sum {fx}}{30}\)
\(\sum {fx}\) = 5 x 30 = 150; 150 - 34 = 116
\(\sum {f}\) = 29
\(\sum {fx}\) = 116
= \(\frac{116}{29}\) = 4
5= \(\frac{\sum {fx}}{30}\)
\(\sum {fx}\) = 5 x 30 = 150; 150 - 34 = 116
\(\sum {f}\) = 29
\(\sum {fx}\) = 116
= \(\frac{116}{29}\) = 4