Question

The state education commission wants to estimate the fraction of tenth grade students that have reading skills at or below the eighth grade level.

Step 2 of 2 :  

Suppose a sample of 966 tenth graders is drawn. Of the students sampled, 802 read above the eighth grade level. Using the data, construct the 98% confidence interval for the population proportion of tenth graders reading at or below the eighth grade level. Round your answers to three decimal places.

Answer 1

We have given,                  
                  
x=966-802=164              
n=966              
Estimate for sample proportion=   0.1698      
Level of significance is =1-0.98=0.02          
Z critical value(using Z table)=2.326          
                  
Confidence interval formula is                  


=(0.142,0.198)
                  
Lower limit for confidence interval=0.142  
                  
Upper limit for confidence interval=0.198