An Analyst wants to know if there was a significance difference in the average of hours worked in a week from 1973

(Group 1) to 2018 (Group 2). He gathers all the data from the General Social Survey, and lists the following summary statistics from the sampling. The General Social Survey uses a method similar to simple random sample. 

(Source: General Social Survey) 

Year

1973

2018

Mean

39.50

40.40

Std. Dev

14.86

12.24

n

30

48

Choose the best answer that explains conditions necessary for a two sample t test. 

 Sampling is taken from the GSS, an extremely reliable source. That is all we need to know.

  We can assume random sampling.

  We can assume this is a volunteer sample.

 Groups are dependent on each other, making them perfect for two mean significance tests.

Question 5

0 / 1 pts

The University of Florida is interested in determining if there is a difference in the average weight gain between male students (group 2) and female students (group 1) during their freshman year. They take a random sample of 10 male students and 10 female students: the data is shown in the table below. Find the confidence interval with 95% confidence.

(Male – Female) 

Female(group 1)Male(group 2)15752081539614512416101181358

a)  (2.06, 9.14) 

b)  (-10.076, -1.124) 

c)  (-2.06, 9.14) 

d)  (-10.076, 1.124)