In: Statistics and Probability
data set
West | SouthEast | MidWest | NewEngland | |
4 | 3 | 2 | 3 | |
7 | 2 | 2 | 3 | |
8 | 4 | 8 | 4 | |
3 | 2 | 9 | 8 | |
4 | 8 | 10 | 7 | |
4 | 3 | 12 | 3 | |
4 | 5 | 1 | 5 | |
5 | 6 | 9 | 6 | |
6 | 2 | 9 | 2 | |
10 | 4 | 3 | 2 | |
9 | 3 | 6 | 1 | |
7 | 3 | 5 | 4 | |
7 | 9 | 6 | 3 | |
4 | 2 | 4 | 3 | |
3 | 3 | 4 | 5 | |
2 | 1 | 4 | 10 | |
1 | 2 | 4 | 10 | |
2 | 1 | 2 | 9 | |
3 | 2 | 2 | 11 | |
9 | 2 | 1 | ||
1 | 1 | |||
1 | ||||
3 | ||||
2 |
Part 1
Using the same data set, analyze the data for Midwest region. Do
the following:
(1) Obtain a histogram and boxplot for the data (revisit one of the
earlier lab reports).
(2) You need to test whether the mean number of years of education
in this region is significantly different from 5.5. State
the hypotheses.
(3) Perform an appropriate test of hypotheses; copy and paste the
results.
(4) Identify the test statistic and the p-value, and state the
decision.
(5) Interpret the p-value (see Week 5 module), and answer the
research question.
Part 2
Using the same data set, consider the data for Southeast and West
regions. Do the following:
(1) You need to test whether there is a significant difference in
the mean number of years of education beyond high school between
the two regions. State the hypotheses.
(2) Perform an appropriate test of hypothesis; copy and paste the
results.
(3) Identify the test statistic and the p-value, and state the
decision.
(4) Interpret the p-value (see Week 5 module), and answer the
research question.
(5) Identify the 95% confidence interval for the mean difference,
and interpret the result. How does this result relate to the
results in parts (3) and (4) Be specific.
Support your conclusion with specific calculations.
Solution:
Part 1.
The histogram for Mid West is the following:
The boxplot for the MidWest is the following:
The null hypothesis is: Mean number of years of education in the Mid West region is equal to 5.5.
The alternative hypothesis is: Mean number of years of education in the Mid West region is different from 5.5.
We perform the test and have the following results tabulated below:
One-Sample Statistics |
||||
N |
Mean |
Std. Deviation |
Std. Error Mean |
|
Mid_West |
21 |
4.9524 |
3.35375 |
.73185 |
One-Sample Test |
||||||
Test Value = 5.5 |
||||||
t |
df |
Sig. (2-tailed) |
Mean Difference |
95% Confidence Interval of the Difference |
||
Lower |
Upper |
|||||
Mid_West |
-.748 |
20 |
.463 |
-.54762 |
-2.0742 |
.9790 |
Here the P-value is = 0.463>0.05, hence we fail to reject the null hypothesis.
Part2.
The null hypothesis is: Mean number of years of education beyond high school between the South East and West regions are equal.
The alternative hypothesis is: Mean number of years of education beyond high school between the South East and West regions are different.
We perform two independent sample t-test and obtain the following result:
Group 1 = West
Group 2 = SouthEast