In: Statistics and Probability
A certain brand of microwave oven was priced at 10 stores in Dallas and 13 stores in San Antonio. The data follow.
Dallas | San Antonio |
---|---|
443 | 461 |
488 | 454 |
403 | 433 |
483 | 478 |
438 | 473 |
448 | 443 |
436 | 428 |
421 | 435 |
431 | 411 |
403 | 420 |
423 | |
458 | |
431 |
Use a 0.05 level of significance and test whether prices for the microwave oven are the same in the two cities.
State the null and alternative hypotheses.
H0: Median price for Dallas − Median price
for San Antonio < 0
Ha: Median price for Dallas − Median price for
San Antonio = 0H0: The two populations of
microwave prices are identical.
Ha: The two populations of microwave prices are
not identical. H0:
Median price for Dallas − Median price for San Antonio ≤ 0
Ha: Median price for Dallas − Median price for
San Antonio > 0H0: Median price for Dallas −
Median price for San Antonio ≥ 0
Ha: Median price for Dallas − Median price for
San Antonio < 0H0: The two populations of
microwave prices are not identical.
Ha: The two populations of microwave prices are
identical.
Find the value of the test statistic.
W =
Find the p-value. (Round your answer to four decimal places.)
p-value =
State your conclusion.
Reject H0. There is not sufficient evidence to conclude that there is a significant difference between the prices for the microwave oven in the two cities.Reject H0. There is sufficient evidence to conclude that there is a significant difference between the prices for the microwave oven in the two cities. Do not reject H0. There is sufficient evidence to conclude that there is a significant difference between the prices for the microwave oven in the two cities.Do not reject H0. There is not sufficient evidence to conclude that there is a significant difference between the prices for the microwave oven in the two cities.
H0: The two populations of microwave prices
are identical.
Ha: The two populations of microwave prices are
not identical.
Dallas | San Antonio | Dallas Values | Dallas Ranks | San Ant.Values | San Ant. Ranks |
---|---|---|---|---|---|
443 | 461 | 403 | 1.5 | 411 | 3 |
488 | 454 | 403 | 1.5 | 420 | 4 |
403 | 433 | 421 | 5 | 423 | 6 |
483 | 478 | 431 | 8.5 | 428 | 7 |
438 | 473 | 436 | 12 | 431 | 8.5 |
448 | 443 | 438 | 13 | 433 | 10 |
436 | 428 | 443 | 14.5 | 435 | 11 |
421 | 435 | 448 | 16 | 443 | 14.5 |
431 | 411 | 483 | 22 | 454 | 17 |
403 | 420 | 488 | 23 | 458 | 18 |
423 | 461 | 19 | |||
458 | 473 | 20 | |||
431 | 478 | 21 | |||
Result Details
Dallas
Sum of ranks: 117
Mean of ranks: 11.7
The expected sum of ranks: 120
The expected mean of ranks: 12
U-value: 68
Expected U-value: 65
San Antonio
Sum of ranks: 159
Mean of ranks: 12.23
The expected sum of ranks: 156
The expected mean of ranks: 12
U-value: 62
Expected U-value: 65
Dallas & San Antonio Combined
Sum of ranks: 276
Mean of ranks: 12
Standard Deviation: 16.1245
Result 1 - U-value
The U-value is 62. The critical value of U at p < .05 is 33. Therefore, the result is not significant at p < .05.
Result 2 - Z-ratio
The Z-Score is 0.15504. The p-value is .87288. The result is not significant at p < .05.
Reject H0. There is not sufficient evidence to conclude that there is a significant difference between the prices for the microwave oven in the two cities.