Question

In what follows use any of the following tests: Regression, multiple regression, one-sided t-test, or two-sided t-test. All conclusions should be based on 5% P-value threshold.

Choose the best fitting answer.

Open Soda_in_Schools data. SETUP: The Schools district compared two schools, one that serves soda drinks for lunch and one that does not. They collected the weight of the students and wanted to see if there is an increase in the weight of the students where soda drinks were served. Given the data, your job is to perform the appropriate statistical test or procedure and help them decide.

1. What test did you perform?

a. Regression
b. ââMultiple regression
c. One-sided t-test
d. ââTwo-sided t-test
2. What is the P-value?

a. 0.982427
b. 0.000193
c. 0.245782
d. 0.122891
e. None of these
3. What is the Statistical interpretation?

a. Since P-value is very small we can conclude that the more soda the students drink the heavier they get.
b. ââSince P-value is too large we cannot conclude that there is an increase in studentsâ weight when soda drinks were served.
c. Since P-value is too large we cannot conclude that studentsâ weight are different for these two schools.
d. None of these.
4. What is the conclusion?

a. Test is inconclusive; thus nothing can be concluded.
b. Test is inconclusive; thus we cannot claim that the average weights are different.
c. Test is inconclusive; thus we cannot claim that there is a correlation between drinking soda and weight.
d. None of these.
Soda_in_Schools data

Soda Yes SodaNO
91 111
108 89
89 97
93 101
114 90
80 89
120 95
104 88
96 80
84 79
73 88
86 97
103 73
107 95
90 89
77 92
91 73

Answer 1

1. Two sided t-test ( d )
2. 0.245782 ( c )
3. Since P-value is too large we cannot conclude that the students’ weight are different for these two schools. ( c )
4. The test is inconclusive; thus we cannot claim that the average weights are different. ( b )

Explanation:

1) Test performed is a Two sided test and this because we are trying to determine the mean difference between two groups irrespective of their direction

2) Determine the P-value ( we will use a data-data analysis approach on excel data sheet while assuming Unequal variances )

yes No

Mean 94.47059 89.76471

Variance 173.2647 95.19118

Observations 17 17

df 30

t Stat 1.184211

P(T<=t) one-tail 0.122814

t Critical one-tail 1.697261

P(T<=t) two-tail 0.245782

Hence The p-value = 0.245782

3) Since P-value is too large we cannot conclude that the students’ weight are different for these two schools.

4) The test is inconclusive; thus we cannot claim that the average weights are different.