The same experimental design discussed in Problem 20 was used to test rats trained to climb a sequence of short ladders. Times in seconds for eight rats to perform this task are shown in the following table.

Do these data indicate that rats receiving larger rewards tend to climb the ladder in less time? Use a 5% level of signifi­cance.

(a) What is the level of signifi­cance? State the null and alternate hypotheses. Will you use a left-tailed, right-tailed, or two-tailed test?

(b) What sampling distribution will you use? What assumptions are you making? Compute the value of the sample test statistic and corresponding t value.

(c) Find (or estimate) the P-value. Sketch the sampling distribution and show the area corresponding to the P-value.

(d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis? Are the data statistically signifi­cant at level a?

(e) Interpret your conclusion in the context of the application.

Time 1 pellet 12.5 13.7 11411.0 10.4 14.6 12.3 Time 5 pellets 11 12.0 2.2 0.6 5 10.5 12.9 11.0