Question

Use the given degree of confidence and sample data to construct a confidence interval for the population proportion p: n = 195, x = 162; 95% confidence.a. 0.788 < p < 0.873.
b. 0.789 < p < 0.873.
c. 0.778 < p < 0.883.
d. 0.777 < p < 0.884.

Answer 1

Answer:

c. 0.778 < p < 0.883.

Step-by-step explanation:

The formula for confidence interval for proportion =

p ± z score × √p(1 - p)/n

p = x/n

n = 195, x = 162

z score for 95% confidence Interval = 1.96

p = 162/195

p = 0.8307692308

p ≈ approximately equal to = 0.8308

0.8308 ± 1.96 × √0.8308 × (1 - 0.8308)/195

0.8308 ± 1.96 ×√0.8308 × 0.1692/195

0.8308 ± 1.96 × √0.0007208788

0.8308 ± 1.96 × 0.0268491862

0.8308 ± 0.052624405

Confidence Interval

= 0.8308 - 0.052624405

= 0.778175595

Approximately = 0.778

= 0.8308 + 0.052624405

= 0.883424405

Approximately = p

0.883

Therefore, the confidence interval for this proportion = (0.778, 0.883) or option c. 0.778 < p < 0.883