An investor believes that investing in domestic and international stocks will give a difference in the mean rate of return. They take two random samples of 15 months over the past 30 years and find the following rates of return from a selection of domestic (Group 1) and international (Group 2) investments. Can they conclude that there is a difference at the 0.10 level of significance? Assume the data is normally distributed with unequal variances. Use a confidence interval method. Round to 4 decimal places.

An engineer is going to redesign an ejection seat for an airplane. the seat was designed for pilots weighing between 120 lb and 161 lb. the new population of pilots has normally distributed weights with a mean of 125 lb and a standard deviation of 28.1 lb. a)if a pilot is randomly selected, find the probability that his weight is between 120 lb and 161 lb.the probability is approximately? b. if 36 different pilots are randomly selected, find the probability that their mean weight is between 120 lb and 161 lb. the probability is approximately? c. when redesigning the ejection seat, which probability is more relevant? . part (b) because the seat performance for a single pilot is more important. b. part (b) because the seat performance for a sample of pilots is more important. c. part (a) because the seat performance for a sample of pilots is more important. d. part (a) because the seat performance for a single pilot is more important.