The sample proportion has an approximately normal distribution, with the mean being the population mean and the standard deviation (i.e. the standard error of the sampling proportion) equal to 
SE = sqrt(p*q/n) where p is the population proportion q is 1-p, and n is the sample size. 
<span>(Typically, for a confkdence interval, the sample proportion and its complement are substituted for p and q.) </span>
The margin of error will be Zc*SE, where Zc is the critical value of Z for the level of confidence required. The confidence interval, then, will be the sample proportion, plus or minus the margin of error. 
For a 90% confidence interval, Zc is 1.645. 
<span>So the margin of error is 1.645 * sqrt(.9*.1/400), roughly .025. So your confidence interval would be around [.875, .925] 
The best and most correct answer among the choices provided by your question is the second choice or letter C which is 3%.
I hope my answer has come to your help. Thank you for posting your question here in Brainly.</span>
        
                    
             
        
        
        
Answer:
what do you need help on?
 
        
             
        
        
        
Step-by-step explanation:
100*77+72/4
100*77+18
7700+18
7718
 
        
                    
             
        
        
        
Answer:
7
Step-by-step explanation:
 
        
                    
             
        
        
        
The following function would be a or d