Find a 95 confidence interval for theta and explain how to i
Solution
a.
 CI = p ± Z a/2 Sqrt(p*(1-p)/n)))
 x = Mean
 n = Sample Size
 a = 1 - (Confidence Level/100)
 Za/2 = Z-table value
 CI = Confidence Interval
 Mean(x)=80
 Sample Size(n)=831
 Sample proportion = x/n =0.096
 Confidence Interval = [ 0.096 ±Z a/2 ( Sqrt ( 0.096*0.904) /831)]
 = [ 0.096 - 1.96* Sqrt(0) , 0.096 + 1.96* Sqrt(0) ]
 = [ 0.076,0.116]
b.
 Set Up Hypothesis
 Null, H0:P=0.1
 Alternate, H1: P!=0.1
 Test Statistic
 No. Of Success chances Observed (x)=80
 Number of objects in a sample provided(n)=831
 No. Of Success Rate ( P )= x/n = 0.0963
 Success Probability ( Po )=0.1
 Failure Probability ( Qo) = 0.9
 we use Test Statistic (Z) for Single Proportion = P-Po/Sqrt(PoQo/n)
 Zo=0.09627-0.1/(Sqrt(0.09)/831)
 Zo =-0.3585
 | Zo | =0.3585
 P-Value: Two Tailed ( double the one tail ) - Ha : ( P != -0.35846 ) = 0.72
 Hence Value of P0.05 < 0.72,Here We Do not Reject Ho

