Question

Suppose a marketing company wants to determine the current proportion of customers who click on ads on their smartphones. It was estimated that the current proportion of customers who click on ads on their smartphones is 0.42 based on a random sample of 100 customers.
Compute a 92% confidence interval for the true proportion of customers who click on ads on their smartphones and fill in the blanks appropriately.

  < p <   (round to 3 decimal places)

Answer 1

Solution :

Given that,

n = 100

Point estimate = sample proportion = = 0.42

1 - = 1-0.42=0.58

At 92% confidence level

Z/2=1.751 ( Using z table )   

Margin of error = E = Z / 2 * (( * (1 - )) / n)

= 1.751(((0.42*0.58) /100 )

= 0.086

A 95% confidence interval for population proportion p is ,

- E < p < + E

0.42-0.086 < p < 0.42+0.086

0.334<p<0.506