USE THIS INFORMAITON TO ANSWER QUESTIONS 5 – 9. A marketing firm in the District
ID: 3360074 • Letter: U
Question
USE THIS INFORMAITON TO ANSWER QUESTIONS 5 – 9.
A marketing firm in the District of Columbia wanted to know if the subway lines traffic from the suburbs to Capitol Hill during rush hour had the same traffic levels. They had no preconceptions about the relative counts. The observed data from the test is below.
They used a significance level of 5%. Red Line Blue Line Yellow Line Green Line TOTAL 591 423 526 460 2000 What type of test should they conduct?
Select one: a. Test of independence b. Test of homogeneity c. Goodness of fit test
What is the correct null hypothesis?
Select one:
a. The traffic on all lines is not the same.
b. The traffic on the lines will be different.
c. The traffic on all lines is the same.
d. All the lines will have traffic.
Given that the total number of commuters is 2000, what number should be in the “expected” cell for the Blue Line?
Select one:
a. 1600
b. 1000
c. 500
d. 800
How is the Chi-square value for each cell calculated?
Select one:
a. Observed - Expected
b. (Observed - Expected)2
c. (Observed - Expected )2 / expected
If the P-value for the test was P = .01, the correct conclusion is
Select one:
a. P < alpha Accept the alternate. The traffic counts are all different.
b. P < alpha Reject the null. The traffic counts are not the same.
c. P > alpha Reject the null. The traffic counts are the same.
d. P > alpha Accept the alternate. The traffic counts are the same.
Explanation / Answer
1st) c. Goodness of fit test
2nd) null hypothesis c. The traffic on all lines is the same.
3rd)expected cell count =total/4 =500
c. 500
4th) c. (Observed - Expected )2 / expected
5th) applying chi square goodness of fit test:
for above test stat and degree of freedom(categories-1=3) ; p value =0.0000
therefore b. P < alpha Reject the null. The traffic counts are not the same.
observed Expected Chi square Type Probability O E=total*p =(O-E)^2/E red 0.250 591.000 500.00 16.56 blue 0.250 423.000 500.00 11.86 yellow 0.250 526.000 500.00 1.35 green 0.250 460.000 500.00 3.20 1 2000 2000 32.9720Related Questions
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