Ask Question
20 July, 10:26

A clinical psychologist wants to test whether experiencing childhood trauma affects one's self-efficacy in adulthood. He randomly selects 231 adults who have experienced childhood trauma and finds that their mean self-efficacy score equals 148.9. The standard deviation of the sample equals 27.4. Self-efficacy scores in the general population of adults are distributed normally with a mean equal to 152.5. Is there sufficient evidence to conclude that the self-efficacy of adults who have experienced childhood trauma differs from that in the general population of individuals

+3
Answers (1)
  1. 20 July, 10:46
    0
    Step-by-step explanation:

    We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean

    For the null hypothesis,

    µ = 152.5

    For the alternative hypothesis,

    µ ≠ 152.5

    This is a two tailed test.

    Since no population standard deviation is given, the distribution is a student's t.

    Since n = 231

    Degrees of freedom, df = n - 1 = 231 - 1 = 230

    t = (x - µ) / (s/√n)

    Where

    x = sample mean = 148.9

    µ = population mean = 152.5

    s = samples standard deviation = 27.4

    t = (148.9 - 152.5) / (27.4/√231) = - 2

    We would determine the p value using the t test calculator. It becomes

    p = 0.047

    Since alpha, 0.05 > thanthere sufficient evidence to conclude that the self-efficacy of adults who have experienced childhood trauma differs from that in the general population of individuals the p value, 0.047, then we would reject the null hypothesis. Therefore, At a 5% level of significance, there is sufficient evidence to conclude that the self-efficacy of adults who have experienced childhood trauma differs from that in the general population of individuals
Know the Answer?