Answer:
79 because x = 7 so 12 x7 - 5 =79
Cross multiply
5/8 and 8/10
5x8=40
8x8=64
40 does not equal 64 so not proportional
Answer:
sample variances
Step-by-step explanation:
The pooled variance method is used to estimate the variance of several different population with different means, but are assume to have the same variance.
The weights represent the sample variances.
So the correct answer is
sample variances
90 for the first one
120 for the second one