In: Statistics and Probability
you may need to use the appropriate technology to answer this question.
Consider the following data on price ($) and the overall score for six stereo headphones tested by a certain magazine. The overall score is based on sound quality and effectiveness of ambient noise reduction. Scores range from 0 (lowest) to 100 (highest).
Brand | Price ($) | Score |
---|---|---|
A | 180 | 74 |
B | 150 | 73 |
C | 95 | 61 |
D | 70 | 58 |
E | 70 | 42 |
F | 35 | 28 |
(a) The estimated regression equation for this data is ŷ = 26.268 + 0.297x, where x = price ($) and y = overall score. Does the t test indicate a significant relationship between price and the overall score? Use α = 0.05.
State the null and alternative hypotheses.
State the null and alternative hypotheses.
H0: β0 = 0
Ha: β0 ≠ 0H0:
β1 = 0
Ha: β1 ≠
0 H0: β1 ≥
0
Ha: β1 < 0H0:
β1 ≠ 0
Ha: β1 = 0H0:
β0 ≠ 0
Ha: β0 = 0
Find the value of the test statistic. (Round your answer to three decimal places.)
Find the p-value. (Round your answer to four decimal places.)
p-value =
What is your conclusion?
Reject H0. We conclude that the relationship between price ($) and overall score is significant.Reject H0. We cannot conclude that the relationship between price ($) and overall score is significant. Do not reject H0. We conclude that the relationship between price ($) and overall score is significant.Do not reject H0. We cannot conclude that the relationship between price ($) and overall score is significant.
(b)
Test for a significant relationship using the F test. Use α = 0.05.
State the null and alternative hypotheses.
H0: β0 ≠ 0
Ha: β0 = 0H0:
β0 = 0
Ha: β0 ≠
0 H0: β1 =
0
Ha: β1 ≠ 0H0:
β1 ≥ 0
Ha: β1 < 0H0:
β1 ≠ 0
Ha: β1 = 0
Find the value of the test statistic. (Round your answer to two decimal places.)
Find the p-value. (Round your answer to three decimal places.)
p-value =
What is your conclusion?
A) Reject H0. We cannot conclude that the relationship between price ($) and overall score is significant.
B) Do not reject H0. We cannot conclude that the relationship between price ($) and overall score is significant.
C) Do not reject H0. We conclude that the relationship between price ($) and overall score is significant
D) Reject H0. We conclude that the relationship between price ($) and overall score is significant.
(c)Show the ANOVA table for these data. (Round your p-value to three decimal places and all other values to two decimal places.)
Source of Variation |
Sum of Squares |
Degrees of Freedom |
Mean Square |
F | p-value |
---|---|---|---|---|---|
Regression | |||||
Error | |||||
Total |
We can perform this analysis in MS Excel as follows
Regression in excel
I performed the analysis using basic commands in MS Excel and I am giving the steps to be followed-
A) The Null hypothesis can be given as
H0: β0 ≠ 0
and alternative hypothesis
Ha: β0 ≠ 0
Now the results from Excel is as follows
As mentioned in question we get the same regression equation
ŷ = 26.268 + 0.297x, where x = price ($) and y = overall score
test statisitc: t= 4.195
p-value = 0.0137 which is less than 0.05
Conclusion: we reject the null hypothesis in favor of the alternative hypothesis
B) & C) Test for a significant relationship using the F test and ANOVA table
The Null hypothesis can be given as
H0: β0 ≠ 0
and alternative hypothesis
Ha: β0 ≠ 0
test statistic: F= 17.598
p-value = 0.0137 which is less than 0.05
Conclusion: we reject the null hypothesis in favor of the alternative hypothesis