In a study of parents who have children with attention deficit/hyperactiviety di

Question

In a study of parents who have children with attention deficit/hyperactiviety disorder (ADHD), parents were asked to rate thier overall stress level using the Parental Stress Scale(PSS). This scale has 18 items that contain statemtns regarding both postive and negative aspects of parenthood. Respondents are asked to rate their agreement with each statement using a 5-point scale (1= strongly disagree to 5 = strongly agree). The scores are summed such that a higher score indicates greater stress. The mean rating for the 50 parents in the study was reported as 52.98 with a stadnard deviation of 10.34

a) Do you think that these data are approximately normally distributed? Explain why or why not

b) Is it appropriate to use the methods of this section to compute a 90% confidence interval? Explain why or why not

c) Find the 90% margin of error and the corresponding confidence interval. Write a sentence explaining the interval and the meaning of the 90% confidence level

d) To recruit parents for the study, the researchers visited a psychiatric outpatient service in Rohtak, India, and selected 50 consectuive families who met the inclusion and exclusion criteria. To what extent do you think the results can be generalized to all parents with children who have ADHD in India or in other locations around the world?

Explanation / Answer

(a) We think that these data are approximately as data comes from a very big population of parents which is normally distributed.

(b) 90% confidence interval can be used here as the data is a categorica varaible where confidence interva can be used.

(c) 90% margin of error = critical test statistic * standard error of mean

critical test statistic = 1.645

standard error of the mean = s/ sqrt(n) = 10.34/ sqrt(50) = 1.4623

90% margin of error = 1.645 * 1.4623 = 2.4054

COnfidence interval = sample mean +- margin of error = 52.98 +- 2.4054 = (50.575, 55.385)

Here the meaning of 90% confidence level is that if we take random sample of 50 parents again and agian then it would be 95% probability that sample mean will have values in between the 95% confidence interval.

(d)Here the data is not randomized. The sample is derived from a single population of one city of Rohtak, India so can not be generalzed to all parents with children who have ADHD.

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.