Data A.1 on page 136, we introduce a study in which mice are randomly separated into one group on a normal light–dark cycle and one group with bright light all the time. Although the mice ate the same amounts and exercised the same, the sample mice with light at night gained more weight. The body mass gain, in grams, after four weeks is shown (rounded to the nearest whole number) in Table B.5 and stored in FatMice18.

Table B.5

We saw in Exercise 4.127 on page 277 that the null and alternative hypotheses for testing whether mean weight gain is higher in the presence of light at night are given by

Use StatKey or other technology to complete the test. State the p-value and state the conclusion of the test in context. How strong is the evidence for the result?

Exercise 4.127

Light at Night Makes Fat Mice? In Data A.1 on page 136, we introduce a study in which mice are randomly separated into one group on a normal light dark cycle and one group with bright light on all the time. Although the mice ate the same amounts and exercised the same, the sample mice with the light at night gained more weight. We wish to determine whether there is evidence that mean weight gain for all mice (not just this sample) is higher in the presence of light at night. The body mass gain, in grams, after four weeks is shown (rounded to the nearest whole number) in Table 4.11.

(a) What are the null and alternative hypotheses?

(b) How can we create one randomization sample?

Create one (using cards or some other physical simulation) and record the results of your simulated sample in a table similar to Table 4.11.

Table 4.11.

Table B.5 Body mass gain of mice, in grams Bright light (LL) 10 10 11 9 12 9 11 9 17 7 8 Light/dark (LD) 6 3 8 6 6 4