Question

Match problems to procedures.

Run times (msec) of a new phone app developed by GotYourGP and established competitor WeTrackYou.Inc. are logged in a data file. At (alpha symbol) = 0.05, are the run times of GotYourGP and WeTrackYou.Inc comparable?

Given weights of 31, 29, 26, 33, 40, 28, 30, and 25, at (alpha symbol) = 0.05 test that the population mean is 35.

Testing that a gasoline additive increases mileage, we compute mpg with additive minus mpg without additive for each car. If the mean of the differences is positive enough, action will be required to implement the additive.

Test size C battery mean life is at least 25 hours.

An effective vaccine would reduce the proportion of exposed persons contracting a disease. A pharmaceutical company wants to test the effectiveness of a new vaccine in preventing a certain disease. It is expected that 40% of unvaccinated exposed people will contract the disease. A group of 48 exposed persons volunteered to be vaccinated. Later, two of the volunteers contracted the disease. Test H0: π ≥ 0.40 (vaccine ineffective) at (alpha symbol) = 0.01.

Key

1. 1-tailed test of proportion with negative critical value

2. 2-tailed test of mean with both negative and positive critical value

3. 1-tailed test of mean with negative critical values

4. 1-tailed test of paired data with positive critical value

5. 2-tailed test of means of 2 independent populations

Answer 1

Ans:

1)

$H_0:\mu =35$

$H_1:\mu \neq 35$

2-tailed test of mean with both negative and positive critical value

2)

d=mpg with additive minus mpg without additive for each car.

$H_a:\mu_d >0$

1-tailed test of paired data with positive critical value

3)

$H_0:\mu\geq 25$

$H_a:\mu< 25$

1-tailed test of mean with negative critical values

4)

H₀: π ≥ 0.40

H₁:π < 0.40

1-tailed test of proportion with negative critical value