Question

It is generally accepted that patients grow anxious when a person with a white coat and stethoscope walks into an examining room; i.e., patients have white coat hypertension. A family practitioner hypothesizes the opposite effect. To test this, the practitioner has colleagues from the practice randomly visit patients in a white coat or non-white sport coat, and measure their blood pressure. What can the practitioner conclude with an α of 0.05? Below are the systolic blood pressures of the patients.

white	non-white
117 116 111 125 119 121 113 118 98	103 98 118 117 116 103 113 112 105

a) What is the appropriate test statistic?
---Select--- na z-test One-Sample t-test Independent-Samples t-test Related-Samples t-test

b)
Condition 1:
---Select--- examining room white coat hypertension non-white coat white coat blood pressure
Condition 2:
---Select--- examining room white coat hypertension non-white coat white coat blood pressure

c) Compute the appropriate test statistic(s) to make a decision about H₀.
(Hint: Make sure to write down the null and alternative hypotheses to help solve the problem.)
p-value =  ; Decision:  ---Select--- Reject H0 Fail to reject H0

d) compute the corresponding effect size(s) and indicate magnitude(s).
If not appropriate, input and/or select "na" below.
d =  ;   ---Select--- na trivial effect small effect medium effect large effect
r² =  ;   ---Select--- na trivial effect small effect medium effect large effect

e) Make an interpretation based on the results.

The systolic blood pressure for patients that where visited by a practitioner with a white coat was significantly higher from patients that were visited by a practitioner in a non-white sport coat.

The systolic blood pressure for patients that where visited by a practitioner with a white coat was significantly lower from patients that were visited by a practitioner in a non-white sport coat.    

The systolic blood pressure for patients that where visited by a practitioner with a white coat did not significantly differ from patients that were visited by a practitioner in a non-white sport coat.

Answer 1

To test the null hypothesis H0: There is no difference between the systolic blood pressure of patients visited by a practitioner with a white coat with that of those visited by a practitioner in a non-white sport coat. ie. µ_d=0

H1:not H0

with level of significance α = 0.05. Since the measurements of blood pressure are taken on the same person under two different conditions we use the paired t-test.

Working:

	White(X)	Non White(Y)	X-Y	(X-Y)^2
1	117	103	14	196
2	116	98	18	324
3	111	118	-7	49
4	125	117	8	64
5	119	116	3	9
6	121	103	18	324
7	113	113	0	0
8	118	112	6	36
9	98	105	-7	49
		SUM(X-Y)=	53	1051

We use the following formula to calculate the t - score

Conclusion: At 5% level of significance we conclude that the systolic blood pressure of patients that were visited by a practitioner with a white coat did not significantly differ from patients that were visited by a practitioner in a non white sport coat.