mean = ∑x/n
mean * N = ∑x
Men ∑x = 20*178 = 3560
Women ∑x = 30*164 = 4920
Combined = (3560+4920)/50 = ?
In a sample of 20 men, the mean height was 178 cm. In a sample of 30 women, the mean height was 164 cm. What was the mean height for both groups put together?
The answer I got by adding the two means and dividing them by 2 is 171 but it is wrong, it must be 169.9, how can I get it?
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