Question

You are testing the claim that having lights on at night increases weight gain (abstract). A sample of 10 mice lived in an environment with bright light on all of the time and 8 mice who lived in an environment with a normal light/dark cycle is given below. Test the claim using a 2% level of significance. Assume the population variances are unequal and that the weight changes are normally distributed. Give answers to 3 decimal places.

Data available at StatKey, choose Mice Wgt Gain-2e data set

Light (x1x1)	Dark (x2x2)
1.71	2.27
4.67	2.53
4.99	2.83
5.33	4
5.43	4.21
6.94	4.6
7.15	5.95
9.17	6.52
10.26
11.67

What are the correct hypotheses?

H₀: _____

H_{a: ______}

Based on the hypotheses, find the following:

1. Test Statistic = _____ (Hint: difference in means from H_a)

2. p-value = _____

3. The correct decision is to: _____

a) Fail to reject the null hypothesis

b) Reject the claim

c) Reject the null hypothesis

d) Accept the alternative hypothesis

e) Accept the null hypothesis

4. The correct summary would be: _____

a) There is enough evidence to reject the claim.

b) There is enough evidence to support the claim.

c) There is not enough evidence to support the claim.

d) There is not enough evidence to reject the claim that sleeping with lights on can cause weight gain.

Answer 1