Asked by Christina
In a survey of 621 males ages 18-64 , 396 say they have gone to the dentist in the past year.
Construct 90% and 95% confidence intervals for the proportion. Interpret the results and compare the widths of the confidence intervals.
Please show step by step. Thank you!
Construct 90% and 95% confidence intervals for the proportion. Interpret the results and compare the widths of the confidence intervals.
Please show step by step. Thank you!
Answers
Answered by
MathGuru
Use confidence interval formulas for proportions.
CI95 = p + or - (1.96)(√pq/n)
...where √ = square root, p = x/n, q = 1 - p, and n = sample size.
CI90 = p + or - (1.645)(√pq/n)
Hint: x = 396, n = 621
Convert all fractions to decimals to work the formulas.
I hope this will help get you started.
CI95 = p + or - (1.96)(√pq/n)
...where √ = square root, p = x/n, q = 1 - p, and n = sample size.
CI90 = p + or - (1.645)(√pq/n)
Hint: x = 396, n = 621
Convert all fractions to decimals to work the formulas.
I hope this will help get you started.