Question

the NIH wants to prove that taking daily asprine reduce the chance of second heart attack with in five years. wiyhout taking the asprine it is known that 35% OF will suffer a second attack with in 5 years. it is decide to use a level of significance of 0.05 a total 225patients particepated by the taking daily asprien following their first heart attack. of those 45 had a second attack within 5 years

a, state the null and alternative haypothesis

b, what is the Z_crit

C,what is Z data

d, do you reject the null hypothesis?

e, state your conclusion using words in the pronlame

Answer 1

a)

null Hypothesis:               Ho:		p	=	0.35
alternate Hypothesis:    Ha:		p	<	0.35

b)

for 0.05 level with left tailed test , critical value of z=

-1.645

c)

sample success                                                           x                    =				45
sample size		n =		225
std error       =Se		=√(p*(1-p)/n) =		0.0318
sample proportion     p̂		x/n=		0.2000
test stat = z                =		(p̂-p)/Se=		-4.72

d)

Decision:as test statitic is in rejection region we reject null hypothesis

e)

Conclusion: we have sufficient evidence to conclude that taking daily asprine reduce the chance of second heart attack with in five years