Question

May
61
57
34
94
101
148
79
228
68
226
201
137
200
71
134
273
98
116
145
145
88
166
140
250
144
188
155
228
213
112
203
187
329
249
169
182
173
126
132
231
243
335
137
177
161

Open Tornadoes_HW6 data. Test if the month of May has more than 130 tornadoes on average.

13. What test/procedure did you perform? (5 points)

• a. One-sided t-test
• b. Two-sided t-test
• c. Regression
• d. Confidence Interval

14. What is the P-value/margin of error? (5 points)

• a. 68.90523
• b. 163.9778
• c. 20.70142
• d. None of these

15. What is the Statistical interpretation? (5 points)

• a. The P-value is much greater than 5% thus we cannot claim that the averages are different.
• b. The P-value is much greater than 5% thus we are very certain that the slope is not zero.
• c. The prediction interval for the true average number of tornadoes for the month of May is [143.2764, 184.6792]
• d. The P-value is much greater than 5% thus we cannot claim that May has more than 130 tornadoes on average

16. What is the conclusion? (5 points)

• a. We are confident that May has a high average of number of tornadoes.
• b. We are confident that the month of May has more than 130 tornadoes on average.
• c. We cannot be confident that the month of May has more than 130 tornadoes on average.
• d. None of these.

Answer 1

13. What test/procedure did you perform?

a. One-sided t-test

Explanation:

Here, we have to use one sample t test for the population mean.

H₀: µ = 130 versus H_a: µ > 130

This is a one tailed t test (Upper tailed/right tailed).

14. What is the P-value/margin of error?

d. None of these

Explanation:

Formula for test statistic is given as below:

t = (Xbar - µ)/[S/sqrt(n)]

From given data, we have

Xbar = 162.9777778

S = 68.90523429

n = 45

df = n – 1 = 44

t = (162.9777778 – 130) / [68.90523429 / sqrt(45)]

t = 3.2105

P-value = 0.0012

(By using t-table)

15. What is the Statistical interpretation?

The P-value is much less than 5% level of significance, thus we claim that May has more than 130 tornadoes on average.

From above part, we have

P-value < α = 0.05

16. What is the conclusion?

b. We are confident that the month of May has more than 130 tornadoes on average.

Explanation:

From above part, we have

P-value < α = 0.05

So, we reject the null hypothesis

There is sufficient evidence to conclude that month of May has more than 130 tomadoes on average.