T-test Problem Solving

1. Evaluate the following for significance

t observed	t critical	Decision (Retain or Reject Ho)
A)	t=1.78	df=15	a=. 05	two-tailed
B)	t=2.18	df=15	a=. 05	two-tailed
C)	t=1.9	df=15	a=. 05	one-tailed
D)	t=1.9	df=15	a=. 01	one-tailed
E)	t=1.45	df=12	a=. 05	two-tailed

1. Twenty-five individuals who were vaccinated by KickVac and twenty-five individuals who were vaccinated by SickVac underwent an Antibody Test to measure their levels of antibodies for Covid-19 six months after getting their second dose. The table below shows the results of the test. Employinga = .05, two tailed, test the hypothesis that the two brands of vaccines are not equal in their efficacy to provide protection against the Covid-19 virus.

	Group 1 (KickVac)	Group 2 (SickVac)
Mean	82	77
Sum of Squares	384.16	1536.64

Please provide the following:

Mean difference
Standard error of the difference between means
df
t critical
t obtained
Decision (fail to reject or reject Ho)