Question

Suppose (0.6002, 0.7998) is a 95% Interval Estimate for (pie), the true population proportion.

a) What was (p), the sample proportion?

b) What was the Margin of Error?

c) What was Zα/2?

d) What was n, the sample size?

e) Interpret, in words, the meaning of the Interval Estimate (0.6002, 0.7998)

Answer 1

Formula for confidence interval for single population proportions : p

Margin of Error : E

Therefore,

confidence interval for single population proportions : p

(a) Given,

(0.6002, 0.7998) is a 95% Interval Estimate for (pie), the true population proportion

Therefore ,

(b) Margin of Error:E

c)

for 95% confidence level = (100-95)/100 = 0.05

/2 = 0.05/2 = 0.025

d)

n, Sample size

n = 81

e) Interpretation

95% confident that the population proportion is with in (0.6002, 0.7998)