Eric wants to estimate the percentage of elementary school children who have a social media account. he surveys 450 elementary school children and finds that 280 have a social media account. identify the values needed to calculate a confidence interval at the 99% confidence level. then find the confidence interval.

The confidence interval for population mean is given by :-

, where is the sample proportion, n is the sample size , is the critical z-value.

The  values needed to calculate a confidence interval at the 99% confidence level are :

Given : Significance level :

Sample size : n=450

Critical value :

Sample proportion:

Now, the  99% confidence level will be :

Hence, the  99% confidence interval is

in problems involving proportions, we can use cross products to test whether two ratios are equal and form a proportion. to find the cross products of a proportion, we multiply the outer terms, called the extremes, and the middle terms, called the means.

hope it

35-60 students are taking math.