In: Statistics and Probability
A market researcher believes that brand perception of one of the
company's products may vary between different groups. After
interviewing 373 persons, the following data was compiled. Can we
conclude that brand perception is dependent on age? Age Favorable
Unfavorable Neutral Total 18-30 80 27 25 132 30-45 73 27 23 123
Over 45 69 25 24 118 Total 222 79 72 373
Step 1 of 8: State the null and alternative hypothesis.
H0:brand perception and age are dependant, Ha: brand perception and
age are independent OR H0:brand perception and age are independent,
Ha:brand perception and age are dependant
Step 2 of 8: Find the expected value for the number of particpants
who are 1818-3030 years old and have a favorable perception of the
brand. Round your answer to one decimal place.
Step 3 of 8: Find the expected value for the number of particpants who are 3030-4545 years old and have a favorable perception of the brand. Round your answer to one decimal place.
Step 4 of 8: Find the value of the test statistic. Round your answer to three decimal places.
Step 5 of 8: Find the degrees of freedom associated with the test statistic for this problem.
Step 6 of 8: Find the critical value of the test at the
0.0250.025 level of significance. Round your answer to three
decimal places.
Step 7 of 8: Make the decision to reject or fail to reject the
null hypothesis at the 0.0250.025 level of significance.
Fail to reject Null hypothesis OR Reject Null hypothesis
Step 8 of 8: State the conclusion of the hypothesis test at the 0.0250.025 level of significance.
Applying chi square test of independence: |
Expected | Ei=row total*column total/grand total | Unfavorable | favorable | nuetral | Total | |
18-30 | 78.563 | 27.957 | 25.480 | 132 | ||
30-45 | 73.206 | 26.051 | 23.743 | 123 | ||
over 45 | 70.231 | 24.992 | 22.777 | 118 | ||
total | 222 | 79 | 72 | 373 | ||
chi square χ2 | =(Oi-Ei)2/Ei | Unfavorable | favorable | nuetral | Total | |
18-30 | 0.0263 | 0.0328 | 0.0090 | 0.0681 | ||
30-45 | 0.0006 | 0.0346 | 0.0232 | 0.0584 | ||
over 45 | 0.0216 | 0.0000 | 0.0656 | 0.0872 | ||
total | 0.0484 | 0.0673 | 0.0979 | 0.2137 | ||
test statistic X2 = | 0.214 |
step 1)
H0:brand perception and age are independent, Ha:brand perception and age are dependant
Step 2 of 8: expected value =78.6
step 3: expected value =73.2
Step 4 of 8: \
test statistic X2 = | 0.214 |
step 5:
degree of freedom(df) =(rows-1)*(columns-1)= | 4 |
step 6:
for 4 df and 0.025 level , critical value χ2= | 11.143 |
step 7:
fail to reject the null
step 8:
we do not have sufficient evidence