Hypothesis test

Preliminary data analyses indicate that the variable

under consideration is normally distributed on each population. Decide, in each case, whether use of the pooled t-test and pooled t-interval procedure is reasonable. Explain your answer.

10.32 x¯1 = 39.04, s1 = 18.82, n1 = 51, x¯2 = 49.92, s2 = 18.97, n2 = 53

In Exercises 10.100 & 10.102, hypothesis tests are proposed. For each hypothesis test,

a. identify the variable. b. identify the two populations. c. identify the pairs. d. identify the paired-difference variable. e. determine the null and alternative hypotheses. f. classify the hypothesis test as two tailed, left tailed, or right tailed.

10.100 Hypnosis and Pain. In the paper “An Analysis of Factors That Contribute to the Efficacy of Hypnotic Analgesia” (Journal of Abnormal Psychology, Vol. 96, No. 1, pp. 46–51), D. Price and J. Barber examined the effects of hypnosis on pain. They measured response to pain using a visual analogue scale (VAS), in centimeters, where higher VAS indicates greater pain. VAS sensory ratings were made before and after hypnosis on each of 16 subjects. A hypothesis test is to be performed to decide whether, on average, hypnosis reduces pain.

10.102 Fiber Density. In the article “Comparison of Fiber Counting by TV Screen and Eyepieces of Phase Contrast Microscopy” (American Industrial Hygiene Association Journal, Vol. 63, pp. 756–761), I. Moa et al. reported on determining fiber density by two different methods. The fiber density of 10 samples with varying fiber density was obtained by using both an eyepiece method and a TV-screen method. A hypothesis test is to be performed to decide whether, on average, the eyepiece method gives a greater fiber density reading than the TV-screen method.