Researches are interested in whether or not the average fuel economy for compact cars is the same as sedan cars. A sample of 36 compact cars and 25 sedan cars is taken. The sample of compacts returns a mean of X 38 miles per gallon and sample variance of s2-25. The sample of sedans returns a sample mean Y 36 with a sample variance of s 49. Let be the population mean of compacts and ?2 for sedans. a. Create a 95% confidence interval for . b. Now create a 95% confidence interval for ?1-112 c. Say the interval from part b. contains 0. What can you say about the difference in the average fuel economy of compact cars versus economy cars.

Alarge university wanted to study the relationship between completing an internship during college and students' future earning potential. prom the same graduating class, they selected a random sample of 80 students who completed an internship and 100 students who did not complete an internship and examined their salaries five years after graduation. they found that there was a statistically higher mean salary for the internship group than for the noninternship group. which of the following interpretations is the most appropriate? a. there could be a confounding variable, such as student major, that explains the difference in mean salary between the internship and no internship groups.b. we cannot infer anything from these data since the distribution of salaries is likely right skewed.c. you cannot draw any valid conclusions because the sample sizes are different.d. more students should complete internships because having an internship produces a higher salary.

Describe how to write a main idea expressed as a bottom-line statement

Warner inc. sells a high-speed retrieval system for mining information. it provides the following information for the year. budgeted actual overhead cost $965,700 $905,000 machine hours 58,570 49,200 direct labor hours 107,300 104,200 overhead is applied on the basis of direct labor hours. compute the predetermined overhead rate. predetermined overhead rate $ per direct labor hour link to text determine the amount of overhead applied for the year. the amount of overhead applied $