the claim that 40% of those person who retired from an individual job before age of 60 would return to work if a suitable job was available, is to be investigated at the 0.02 level of risk. If 74 out of 200 workers sampled said they would return to work what is our decision? Solution Ho: p=0.4 Ha: p not equal to 0.4 The test statistic is Z=(phat-p)/sqrt(p*(1-p)/n) =(74/200-0.4)/sqrt(0.4*0.6/200) =-0.87 Given a=0.02, the critical values are Z(0.01)=-2.33 or 2.33 Since Z=-0.87 is larger than -2.33, we do not reject Ho. So we can conclude that 40% of those person who retired from an individual job before age of 60 would return to work if a suitable job was available.

1. the claim that 40% of those person who retired from an individual job before age of 60 would
return to work if a suitable job was available, is to be investigated at the 0.02 level of risk. If 74
out of 200 workers sampled said they would return to work what is our decision?
Solution
Ho: p=0.4
Ha: p not equal to 0.4
The test statistic is
Z=(phat-p)/sqrt(p*(1-p)/n)
=(74/200-0.4)/sqrt(0.4*0.6/200)
=-0.87
Given a=0.02, the critical values are Z(0.01)=-2.33 or 2.33
Since Z=-0.87 is larger than -2.33, we do not reject Ho.
So we can conclude that 40% of those person who retired from an individual job before age of 60
would return to work if a suitable job was available