A student earned grades of 84, 78, 84, and 72 on her four regular tests. She earned a grade of 78
on the final exam and 86 on her class projects. Her combined homework grade was 87. The four
regular tests count for 40% of the course grade, the final exam counts for 30%, the project counts
for 10%, and homework counts for 20%. What is her weighted mean grade? Round to one
The table below describes the smoking habits of a group of asthma sufferers. If one of the 1156
people is randomly selected, find the probability that the person is a man or a heavy smoker.
Round to three decimal places as needed.
Find the area of the shaded region. The graph depicts the standard normal distribution with mean
0 and standard deviation 1. Round to four decimal places. -1.82<2
Given the linear correlation coefficient
and the sample size
, determine the critical values of
and use your finding to state whether or not the given represents a significant linear correlation.
Construct the indicated confidence interval for the difference between the two population means.
Assume that the two samples are independent simple random samples selected from normally
distributed populations. Do not assume that the population standard deviations are equal.