Question

9. Mind over matter? David Blaine is determined to know if hypnotism can increase strength. Using his mastery of the mysterious powers of the mind, he runs the following experiment. Shown below are the Weight (in pounds) the subjects could bench press before and after hypnotism. Test the claim that hypnotism is effective in increasing strength? Use a significance level of .05. Subject 1 2 3 4 5 6 7 8 Before 210 230 182 205 262 253 219 216 After 219 236 179 204 270 250 222 216

Answer 1

Answer Date: 11/03/2020 is effective in increasing strength at 5% To test the hypothesis is that hypnotism significance level. The null and alternative hypothesis is, H:Hq = 0 H:Hq <0 The t-test statistics is, First, compute the difference then find mean and standard deviation for computing the t- test statistics.

The mean difference table is, Difference 219 Before After 210 230 236 182 179 205 204 262 270 253 250 219 222 216 216 222.125 | 224.500 | Mean 0 -2.375 From the table, the mean difference is -2.375.

The standard deviation is, (d, -d)? Vn-1 [-9-(-2.375)] +(-6-(-2.375)] + ... +(-3-(-2.375)] + [0-(-2.375)]? 8-1 = 4.8385 The t-test statistics is, - 2.375 7(4.8385)2/8 = -1.388 The t-test statistics is - 1.388.

The t critical value is, The sample size is small and left-tailed test. Look in the column headed a = 0.05 and the row headed in the t distribution table by using degree of freedom is, d.f.=n-1 = 8-1 The t critical value is - 1.895). Decision The conclusion is that the t value corresponds to sample statistics is not fall in the critical region, so the null hypothesis is not rejected at 5% level of significance. There is insufficient evidence to indicate that hypnotism is effective in increasing strength. The result is not statistically significant.