Use Excel to test. For each paired difference, compute After - Before.In the Data Analysis, t-Test:

Paired Two Sample for means, select the After data for Variable 1 Range.Note that the critical

value output by Data Analysis for this test is always positive.In this problem, the sign of the

critical value is negative corresponding to a 1-tailed test with lower reject region and negative

lower critical value.

PersonBefore After

1176 164

2192 191

3 185 176

4 177 176

5 196 185

6 178 169

7 196 196

8 181 172

9 158 158

10 201 193

11 191 185

12 193 189

13 176 175

14 212 210

15 177 173

16 183 180

17 210 204

18 198 192

19 157 152

20 213 200

21 161 161

22 177 166

What is the critical t-value?

Select from the following answer

a) 5.614or-5.614

b) 3.645or-3.645

c) 1.711or-1.711

d) 7.861or-7.861