In: Statistics and Probability
A meteorologist states that the standard deviation of the number of deaths annually from volcanoes in Hawaii is greater than 36. If a random sample of 16 years had a standard deviation of 40, is the claim believable? Use a=0.1
Solution:
Given:
Claim: the standard deviation of the number of deaths annually from volcanoes in Hawaii is greater than 36.
that is:
Sample size = n = 16
Sample standard deviation = s = 40
Level of significance = 0.1
Step 1) State H0 and H1:
Vs
this is right tailed test ( > )
Step 2) Test statistic:
Step 3) Find Chi-square critical value:
df = k - 1 = 16 -1 = 15
Level of significance = 0.10
Chi-square critical value = 22.307
Step 4) Decision Rule:
Reject null hypothesis H0, if Chi square test statistic >
Chi-square critical value =22.307, otherwise we fail to reject
H0.
Since Chi square test statistic =
< Chi-square critical value =22.307, we fail to
reject H0.
Step 5) Conclusion:
At 0.10 level of significance , there is not sufficient evidence to support the claim that the standard deviation of the number of deaths annually from volcanoes in Hawaii is greater than 36.