An inventor wants to test whether a new spray layer that is designed for bicycle tires for tread durability will make a difference. To test the new layer, the inventor randomly selected 12 bicycles. The mean amount of depth of tire tread and standard deviation with the layer is 1.38 and 0.32, respectively. The mean amount of depth of tread and standard deviation without the layer is 1.25 and 0.25, respectively. The mean amount of depth of tread and standard deviation of the difference of the 12 bicycles is 0.13 and 0.11. Assume =0.05.

Question 13

What is the test statistic?

(a) 4.09

(b) 1.1

(c) 3.9

(d) 0.78

Question 14:

What is the rejection region?

(a) t<-1.796 or t>1.796

(b) t<-2.201 or t>2.201

(c) t<-1.717 or t>1.717

(d) t<-2. 074 or t>2.074

Question 15:

What is the p-value?

(a) (0.0005, 0.001)

(b) (0.2, 0.3)

(c) (0.1, 0.15)

(d) (0.001, 0.002)