Question

3. In a comparison of visual acuity of deaf and hearing children, eye movement rates are taken on 8 deaf and 8 hearing children. A clinical psychologist believes that deaf children have greater visual acuity than hearing children. Test the psychologist's claim by using the data in the table. (The larger a child's eye movement rate, the more visual acuity the child possesses.) Let α = 0.05. Deaf children 2.45 3.14 3.23 2.30 2.64 1.95 2.17 2.45 Hearing children 1.15 1.95 1.43 1.73 1.75 1.33 2.03 1.64 Ho: The visual acuity of the two groups is identical. Ha: The visual acuity of the deaf children is greater than the visual acuity of the hearing children. a. Rank the combined data and calculate the Wilcoxon test statistic T. This is a rank sum test. b. Specify the critical region and make a decision about Ho. c. Even though the samples sizes do not exceed 10, conduct the approximate z-test. Use the formula that ignores the ties. Find the test statistic, the p-value and make a decision. Let alpha = 0.05.

Answer 1