Reading proficiency:An educator wants to construct a

99.8

%

confidence interval for the proportion of elementary school children in Colorado who are proficient in reading.Part:0 / 3

0 of 3 Parts Complete

Part 1 of 3

(a) The results of a recent statewide test suggested that the proportion is

0.76

. Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of0.07

?

A sample of202

elementary school children is needed to obtain a99.8

%

confidence interval with a margin of error of0.07

.

Part:1 / 3

1 of 3 Parts Complete

Part 2 of 3

(b) Estimate the sample size needed if no estimate of

p

is available.

A sample of

elementary school children is needed to obtain a99.8

%

confidence interval with a margin of error of0.07

.