Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

9.1.12 Statistics students were surveyed and two of the questions they were aske

ID: 3258393 • Letter: 9

Question

9.1.12 Statistics students were surveyed and two of the questions they were asked was what type of cellphone they use (Basic, iPhone, Smart Phone that is not an iPhone) and how much sleep they typically get on a school night in hours to see if there is an association between sleep and type of phone. For the purposes of this exercise, we will consider this sample to be representative of all students at the school. The summary statistics are shown in the following table and the data are shown in the dotplots.

Type of phone

Sample size

Mean

Standard deviation

Smart Phone

18

7.47

1.00

iPhone

61

7.27

1.07

Basic

15

6.40

1.08

a. Identify the explanatory variable and the response variable in this study.

b. State, in words or symbols, the null and alternative hypotheses.

c. Using the summary statistics given, compute the MAD statistic.

d. A null distribution for this study is shown above. Using the MAD statistic you calculated in part (c), will the p-value for this test be large or small? Explain.

e. Does it appear there is an association between type of cell phone used and the amount of sleep students get? If so, can you conclude that the type of cell phone being used is causing the difference in sleep times?

Type of phone

Sample size

Mean

Standard deviation

Smart Phone

18

7.47

1.00

iPhone

61

7.27

1.07

Basic

15

6.40

1.08

Smart iPhone Basic Sleep 10

Explanation / Answer

(a) explanatory variables are the types of phone used and response variable is sleep(hours)

(b) Ho: No association between types of phone and hours of sleep vs H1: There is association between types of phone and hours of sleep

(c) It is not possible to extract data only from the column diagram as the time points are not given exactly

Comment other informations !