Solutions Statistics

Interpreting independent t-test results—below is SPSS output for an independent t-test comparing sys

Question: Interpreting independent t-test results—below is SPSS output for an independent t-test comparing systolic blood pressure (SBP) of those who survived a myocardial infarction (MI) (survtime = 2) and those who did not (survtime = 1). Based on these results, answer the following: a) What do the highlighted Levene’s test results tell us? b) In light of your answer to “a”, which t-test result should be reported and why? c) What is the interpretation of these results (i.e., specifying outcome vis-à-vis likelihood of surviving an MI episode with respect to sbp)?

Group Statistics

	survtime	N	Mean	Std. Deviation	Std. Error Mean
sbp	1.00	39	145.1282	18.76051	3.00409
	2.00	78	132.0513	12.62434	1.42943

Independent Samples Test

		Levene's Test for Equality of Variances		t-test for Equality of Means
		F	Sig.	t	df	Sig. (2-tailed)	Mean Difference	Std. Error Difference	95% Confidence Interval of the Difference
									Lower	Upper
sbp	Equal variances assumed	32.330	.000	4.465	115	.000	13.07692	2.92870	7.27572	18.87812
	Equal variances not assumed			3.931	55.745	.000	13.07692	3.32683	6.41181	19.74203