A large national company is considering negotiating cellular phone rates for its employees.The Human Resource department would like to estimate the proportion of its employee population who own an Apple iPhone.A random sample of size 250 is taken and 40% of the sample own and iPhone.The 95% confidence interval to estimate the population proportion is _______.
A)0.35 to 0.45
B)0.34 to 0.46
C)0.37 to 0.43
D)0.39 to 0.41
E)0.40 to 0.42

Question

Quizplus · Accepted Answer

The 95% confidence interval for a proportion is calculated using the formula: p̂ ± Z * sqrt((p̂(1-p̂))/n), where p̂ is the sample proportion (0.40), Z is the Z-score for 95% confidence (approximately 1.96), and n is the sample size (250). This calculation results in the interval 0.34 to 0.46.

A Large National Company Is Considering Negotiating Cellular Phone Rates