Question

A survey reveals that trauma patients who seek care at an urban health and wellness clinic experienced differing rates of wound healing. Specifically, over a 4-week period, 40% reported 0-25% wound healing, 30% reported 26-50% wound healing, 20% reported 51-75% wound healing, and 10% reported 76-100% wound healing. Researchers recruit a sample of 250 participants into an observational study and assesses their wound healing again after 4-weeks. The results are displayed in the table below:

Percent Wound Healing	0-25%	26-50%	51-75%	76-100%
Number of Patients	110	70	50	20

Is there evidence at the 5% level to suggest that the distribution of wound healing in this sample is different from those from the previous study? NO

1. Set up hypotheses and determine level of significance.

H0: ________________________________________________________________

___________________________________________________________________

H1: ________________________________________________________________

___________________________________________________________________

α =

2. The equation is supplied below, but indicate WHAT TYPE of Chi-square test you need to conduct:

1. Goodness-of-Fit Test

2. Test of Independence

                        

3. Set up decision rule.

df = k-1 =  

Therefore, reject H0 if χ2 > ______________________________________________

4. Compute the test statistic.

Compute expected values

                        np1-0 =

                        np2-0 =

                        np3-0 =

                        np4-0 =

Percent Wound Healing	0-25%	26-50%	51-75%	76-100%	Total
Number of Patients (O)	110	70	50	20	250
Number of Patients (E)

5. Conclusion.

Do we accept or reject the null hypothesis? ________________________________

___________________________________________________________________

What evidence do we have to accept or reject the null hypothesis? ______________

_________________________________________________________________________

What is the p-value associated with the evidence we obtained? _________________

___________________________________________________________________

Answer 1