Question

Proportion Problem. Each year Delta Dental does a survey of parents concerning the tradition of the Tooth Fairy. A random sample of 1,058 parents were asked about how much money they leave for a tooth and questions concerning how their child responded to the concept of the Tooth Fairy. In one question, 508 parents indicated that their child saved the money they got for their tooth.

You are asked to calculate a 99% Confidence Interval for this proportion.

What is the Lower Value in this Confidence Interval? I just want the answer. Use 4 decimal places for your answer and use the proper rules of rounding.

Answer 1

Sol does a survey of parents concerning Given: Each year della dental cioes a survey of parer the bradition of the tooth fairy. A random sample of poorents n= 1058. Indicated parents for their child saved the money they got for theit tooth () = 508 interval: To Calculate 99.7. confidence we know that: Point estimate = Sample proportion = 508 1058 = 0.4802 2 = 1 - point estimate (ov) Sample proportion - 1 - 0.1802 = 0.5198 let a = 0.5 iyu - ose = 0.2.5. - 05.95 = .546 0.25 We know that, Margin of error = (E) = Sample pooportion x 2 ?X | 10.1802 %0.5198 = 2.576x 1058 = 10.24 96 2.576x 1058

= 2.576 * Ja 3591 x10 4 = 2.576 X 0:01536 = 0.03957 - Margin of error = 0,0396 A 9911.confidence interval for pooportion P, is Sample proportion – E <p a sample proportion +E 014802 -0.0396 <pe 0.4802 +0.0396 0.4406 <p < 0.5198 :. the range of confidence interval is (04406,0.5198)