Question

Understanding student Growth. Over the course of Resh’s teaching career, He decides to understand how learning is changing from semester to semester. His theory is that if an instructor is easy to approach then students get better scores in the class. He decides to compare the student in 2018 between another instructor (Group A) and his classes (Group B).

Note: Group B will have an instructor that is approachable, friendly, funny and Charismatic. Group A will have an instructor that lacks all the qualities of group A instructor (yikes). After preliminary calculations, the descriptive statistics are as follows:

	Group A	Group B
Mean	64.2 pts	93.3 pts
Standard Deviation	13.1 pts	8.12 pts
Sample Size	231	120

Resh’s wants to understand if group A is statistically different from Group B.

a)List all Assumptions. (1pt)

b)State the null and alternative hypothesis(2pt)

c)Choose the test statistic. Explain your reasoning.(2pt)

d)Calculate the 95% CI for Group A. (1pt)

e)Calculate the test statistic to compare the means. (2pt)

f)Given a alpha=.05 and regarding the Hypothesis, What decision should the researcher make? (1pt)

g)State a conclusion that the researcher should reach based on these results (2pt)

Answer 1

a)

Groups are independent from each other.

Samples are random samples.

Since samples are large so we can assume that normality assumption has been fulfilled.

b)

c)

We will use t test statistics since population standard deviatons are unknown.

d)

e)

f)

g)

Conclusion: There is evidence to conclude that  group A is statistically different from Group B.