SOLUTION: If we wish to have a 98% confidence interval, what would be the value of a/2? show how you arrived at this answer

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Question 611086: If we wish to have a 98% confidence interval, what would be the value of a/2? show how you arrived at this answer
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi, 

If we wish to have a 98% confidence interval, what would be the value of a/2? 

a/2 = .01  and using Excel function NORMSINV(0.01)= -2.326 or NORMSINV(.99) = 2.326

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	a	a/2	crtical regions	

80%	0.2	10%	z <-1.28155	z >+1.28155

90%	0.1	5%	z <-1.645	          z >+1.645

92%	0.8	4%	z <-1.751	          z >+1.751

95%	0.05	2.50%	z <-1.96	          z >+1.96

98%	0.02	1%	z <-2.326	          z >+2.326

99%	0.01	0.50%	z<-2.576	          z >+2.576