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 | 71 |
C | 95 | 59 |
D | 70 | 56 |
E | 70 | 40 |
F | 35 | 24 |
(a)
The estimated regression equation for this data is
ŷ = 22.328 + 0.317x,
where x = price ($) and y = overall score. Does the t test indicate a significant relationship between price and the overall score? Use α = 0.05.
State the null and alternative hypotheses.
H0: β1 = 0
Ha: β1 ≠
0H0: β1 ≥ 0
Ha: β1 <
0 H0:
β0 ≠ 0
Ha: β0 =
0H0: β0 = 0
Ha: β0 ≠
0H0: β1 ≠ 0
Ha: β1 = 0
Find the value of the test statistic. (Round your answer to three decimal places.)
Find the p-value. (Round your answer to four decimal places.)
p-value =
What is your conclusion?
Do not reject H0. We conclude that the relationship between price ($) and overall score is significant.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.Reject H0. We cannot conclude that the relationship between price ($) and overall score is significant.
(b)
Test for a significant relationship using the F test. Use α = 0.05.
State the null and alternative hypotheses.
H0: β1 = 0
Ha: β1 ≠
0H0: β1 ≠ 0
Ha: β1 =
0 H0:
β1 ≥ 0
Ha: β1 <
0H0: β0 ≠ 0
Ha: β0 =
0H0: β0 = 0
Ha: β0 ≠ 0
Find the value of the test statistic. (Round your answer to two decimal places.)
Find the p-value. (Round your answer to three decimal places.)
p-value =
What is your conclusion?
Do not reject H0. We cannot conclude that the relationship between price ($) and overall score is significant.Do not reject H0. We conclude that the relationship between price ($) and overall score is significant. Reject H0. We conclude that the relationship between price ($) and overall score is significant.Reject H0. We cannot conclude that the relationship between price ($) and overall score is significant.
(c)
Show the ANOVA table for these data. (Round your p-value to three decimal places and all other values to two decimal places.)
Source of Variation |
Sum of Squares |
Degrees of Freedom |
Mean Square |
F | p-value |
---|---|---|---|---|---|
Regression | |||||
Error | |||||
Total |
SSE =Syy-(Sxy)2/Sxx= | 314.3194 |
s2 =SSE/(n-2)= | 78.5798 | |
std error σ = | =se =√s2= | 8.8645 |
estimated std error of slope =se(β1) =s/√Sxx= | 0.0725 |
a)
H0: β0 = 0
Ha: β0 ≠ 0
test stat t = | (bo-β1)/se(β1)= | = | 4.369 |
p value: | = | 0.0120 |
Reject H0. We conclude that the relationship between price ($) and overall score is significant
b)
H0: β1 = 0
Ha: β1 ≠ 0
value of the test statistic =19.08
p value =0.012
Reject H0. We conclude that the relationship between price ($) and overall score is significant.
c)
Source | SS | df | MS | F | p value |
regression | 1499.68 | 1 | 1499.68 | 19.08 | 0.012 |
Residual error | 314.32 | 4 | 78.58 | ||
Total | 1814.00 | 5 |