Use the one-proportion z-interval procedure to find the required confidence interval.
-A survey of 300 union members in New York State reveals that 112 favor the Republican candidate for governor. Construct the 98% confidence interval for the proportion of all New York State union Members who favor the Republican candidate.
A)0.301 to 0.445
B)0.308 to 0.438
C)0.316 to 0.430
D)0.304 to 0.442

Question

Use the one-proportion z-interval procedure to find the required confidence interval.
-A survey of 300 union members in New York State reveals that 112 favor the Republican candidate for governor. Construct the 98% confidence interval for the proportion of all New York State union Members who favor the Republican candidate. 
A)0.301 to 0.445
B)0.308 to 0.438
C)0.316 to 0.430
D)0.304 to 0.442

Quizplus · Accepted Answer

The sample proportion is 112/300 = 0.3733. Using the one-proportion z-interval formula with a 98% confidence level, the interval is calculated as 0.3733 ± 2.33 * sqrt((0.3733*(1-0.3733))/300), which results in the interval 0.308 to 0.438.

Use the One-Proportion Z-Interval Procedure to Find the Required Confidence