A Researcher Wishes to Determine the Difference in Two Population

Multiple Choice

A researcher wishes to determine the difference in two population means.To do this, she randomly samples 9 items from each population and computes a 90% confidence interval.The sample from the first population produces a mean of 780 with a standard deviation of 240.The sample from the second population produces a mean of 890 with a standard deviation of 280.Assume that the values are normally distributed in each population.The point estimate for the difference in the means of these two populations is _______.

A) -110
B) 40
C) -40
D) 0
E) 240