Final answer:
The point estimate for the difference between the means of the two populations is 3.
Step-by-step explanation:
The point estimate for the difference between the means of the two populations can be calculated using the formula:
Point estimate = Sample mean 1 - Sample mean 2
In this case, the point estimate is:
Point estimate = 45 - 42 = 3
Therefore, the point estimate for the difference between the means of the two populations is 3.