Question

if the state infant death rate of 5.94 increased to 6.03 in a one year period, is that increase something that should cause concern?

Confidence interval: 95%

STD: 2.5

Answer 1

Initial state infant death rate = mu1 = 5.94

Increase state infant death rate = mu2 = 6.03

STD = 2.5

To check if the increase is significant

Null hypothesis : There is no significant different among the two means, mu2=mu1

Alternate hypothesis : There is significant increase in the state infant death rate, mu2>mu1

z = ( mu2-mu1 ) / STD = ( 6.03 - 5.94 ) / 2.5 = 0.036

Confidence interval 95%, therefore alpha = 0.05

Z critical value at alpha = 0.05 in one tailed test = 1.654

Since, z < z critical , we failed to reject null hypothesis

Hence, null hypothesis is accepted.

Or, There is no significant different among the two means, mu2=mu1

or, the increase in state infant death rate is not significant