The mean and standard deviation of a population are 200 and 20, respectively. What is the probability of selecting 64 data values with a mean between 195 and 200?
A. 5.1%
B. 4.8%
C. 48%
D. 49%
The expected value of the difference of two sample means equals the difference of the corresponding population means:
A. Only if the populations are normally distributed
B. Only if the populations are approximately normal and the sample sizes are large
C. Only if the samples are independent
D. All of the above
