Answer: 6
Explanation:
According to the given formation , we have
Today Five Years Ago
Sample mean

Variance (
) 112 24
Sample size (n) 45 36
We know that , the point estimate for the difference between the means of the two populations is the difference between the sample means .
Then, the point estimate for the difference between the means of the two populations is
Hence, the point estimate for the difference between the means of the two populations is 6 .