In: Statistics and Probability
There is a lot of interest in the relationship between studying music and studying math. We will look at some sample data that investigates this relationship. Below are the Math SAT scores from 8 students who studied music through high school and 11 students who did not. Test the claim that students who study music in high school have a higher average Math SAT score than those who do not. Test this claim at the 0.05 significance level.
The 8 students who studied music in high school (x1)
Math SAT Scores (x1) | x1 | s12 | s1 | ||||||||||||||||
|
581.6 | 1280.8 | 35.79 | ||||||||||||||||
The 11 students who did not study music in high school (x2)
Math SAT Scores (x2) | x2 | s22 | s2 | ||||||||||||||||||||||
|
523.0 | 992.8 | 31.51 | ||||||||||||||||||||||
If you are using software, you should be able copy and paste the data.
(b) Use software to calculate the test statistic or use the formula
t =
(c) Use software to calculate the degrees of freedom
(d.f.) or use the formula
Round your answer to the nearest whole
number.
d.f. =
(d) What is the critical value of t? Use the
answer found in the t-table or round to 3 decimal
places.
tα =
(b) Use software to calculate the test statistic.
Test statistic = t = 3.7051
(c) Use software to calculate the degrees of freedom (d.f.)
d.f. = 14
d) What is the critical value of t?
tα = 1.761
(by using t-table)
The required output for the two sample t test for the difference between two population means by assuming unequal population variances is given as below:
Separate-Variances t Test for the Difference Between Two Means |
|
(assumes unequal population variances) |
|
Data |
|
Hypothesized Difference |
0 |
Level of Significance |
0.05 |
Population 1 Sample |
|
Sample Size |
8 |
Sample Mean |
581.625 |
Sample Standard Deviation |
35.7888 |
Population 2 Sample |
|
Sample Size |
11 |
Sample Mean |
523 |
Sample Standard Deviation |
31.5087 |
Intermediate Calculations |
|
Numerator of Degrees of Freedom |
62679.8573 |
Denominator of Degrees of Freedom |
4476.5286 |
Total Degrees of Freedom |
14.0019 |
Degrees of Freedom |
14 |
Standard Error |
15.8228 |
Difference in Sample Means |
58.6250 |
Separate-Variance t Test Statistic |
3.7051 |
Upper-Tail Test |
|
Upper Critical Value |
1.7613 |
p-Value |
0.0012 |
Reject the null hypothesis |