Question

A medical investigator claims that the average number of infections per week at a hospital in Southwestern Pennsylvania is 16.3. A random sample of 12 weeks had a mean number of 17.7 infections per week with a standard deviation of 1.8 infections per week. Use a 1% significance level to test the investigator’s claim that the mean number of infections per week is 16.3.

Students will need to utilize the excel functions: t.dist(), t.dist.2t(), and t.dist.rt() in this activity.
Fill in the blanks with the appropriate responses:

Hypotheses
H₀: The mean number of infections per week is equal to 16.3
H₁: The mean number of infections per week is ________16.3
(type in “less than”, “greater than”, or “not equal to”)

Results
t = _________(enter the test statistic, use 2 decimal places).
p-value = __________(round answer to nearest thousandth of a percent – i.e. 0.012%).

Conclusion
We _________sufficient evidence to support the claim that the mean number of infections per week is ___________ 16.3 (p ___________0.01)
(Use “have” or “lack” for the first blank, “less than”, “greater than”, or “not equal to” for the second blank, and “<” or “>” for the final blank).

Follow Up
What would our conclusion be at the 5% significance level?

We _____________ sufficient evidence to support the claim that the mean number of infections per week is _____________ 16.3 _______________ (p  0.05).
(Use “have” or “lack” for the first blank, “less than”, “greater than”, or “not equal to” for the second blank, and “<” or “>” for the final blank).

Answer 1