In: Statistics and Probability
A police department released the numbers of calls for the different days of the week during the month of October, as shown in the table to the right. Use a 0.01 significance level to test the claim that the different days of the week have the same frequencies of police calls. What is the fundamental error with this analysis?
Day Sun Mon Tues Wed Thurs Fri Sat
Frequency 153 210 224 248 174 212 231
Determine the null and alternative hypotheses.
Upper H 0: (1)
Upper H 1:
(2) Calculate the test statistic (Round to three decimal places as needed.)
(3) Calculate the P-value (Round to four decimal places as needed.)
(4) What is the conclusion for this hypothesis test?
A. Reject Upper H 0. There is sufficient evidence to warrant rejection of the claim that the different days of the week have the same frequencies of police calls.
B. Fail to reject Upper H 0. There is insufficient evidence to warrant rejection of the claim that the different days of the week have the same frequencies of police calls
C. Fail to reject Upper H 0. There is sufficient evidence to warrant rejection of the claim that the different days of the week have the same frequencies of police calls.
D. Reject Upper H 0. There is insufficient evidence to warrant rejection of the claim that the different days of the week have the same frequencies of police calls.
(5) What is the fundamental error with this analysis?
A. Because October has 31 days, two of the days of the week occur more often than the other days of the week.
B. Because October has 31 days, one of the days of the week occur more often than the other days of the week.
C. Because October has 31 days, each day of the week occurs the same number of times as the other days of the week.
D. Because October has 31 days, three of the days of the week occur more often than the other days of the week.
(1) Police calls occur with the same frequency on the different days of the week.
At least one day has a different frequency of calls than the other days.
Police calls occur with all different frequencies on the different days of the week.
At least two days have a different frequency of calls than the other days.
(2) Police calls occur with all different frequencies on the different days of the week.
At least one day has a different frequency of calls than the other days.
Police calls occur with the same frequency on the different days of the week.
At least two days have a different frequency of calls than the other days.
Upper H 0: (1) Police calls occur with the same frequency on the different days of the week.
H 1: At least one day has a different frequency of calls than the other days.
2)
applying chi square goodness of fit test: |
relative | observed | Expected | residual | Chi square | |
category | frequency(p) | Oi | Ei=total*p | R2i=(Oi-Ei)/√Ei | R2i=(Oi-Ei)2/Ei |
1 | 1/7 | 153 | 207.43 | -3.78 | 14.282 |
2 | 1/7 | 210 | 207.43 | 0.18 | 0.032 |
3 | 1/7 | 224 | 207.43 | 1.15 | 1.324 |
4 | 1/7 | 248 | 207.43 | 2.82 | 7.935 |
5 | 1/7 | 174 | 207.43 | -2.32 | 5.387 |
6 | 1/7 | 212 | 207.43 | 0.32 | 0.101 |
7 | 1/7 | 231 | 207.43 | 1.64 | 2.679 |
total | 1.000 | 1452 | 1452 | 31.7397 | |
test statistic X2 = | 31.740 |
3)
p value = | 0.0000 |
A. Reject Upper H 0. There is sufficient evidence to warrant rejection of the claim that the different days of the week have the same frequencies of police calls.
D. Because October has 31 days, three of the days of the week occur more often than the other days of the week.