SOLUTION: Qustion: A survey of 950 car owners found that 28% of the cars are named Lexus. Find the 99% confidence interval of the true proportion of cars named Lexus.

Question 387159: Qustion: A survey of 950 car owners found that 28% of the cars are named Lexus. Find the 99% confidence interval of the true proportion of cars named Lexus.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A survey of 950 car owners found that 28% of the cars are named Lexus. Find the 99% confidence interval of the true proportion of cars named Lexus.
-----------
p-hat = 0.28
---
ME = z*sqrt[pq/n]
= 2.5758*sqrt[0.28*0.72/950]
---
= 0.0375
=============
99% CI: 0.28-0.0375 < p < 0.28+0.0375
----
99% CI: 0.2425 < p < 0.3175
==============================
Cheers,
Stan H.

RELATED QUESTIONS
Find 95% confidence interval for the average monthly comprehensive car insurance premium... (answered by Alex.33)

QUESTION 2 2.1 What determines use of t-distribution and z-distribution in... (answered by ikleyn)

2.1 What determines use of t-distribution and z-distribution in confidence interval... (answered by ikleyn)

A survey of 4,581 U.S. households that owned a mobile phone found that 58 percent are... (answered by stanbon)

when 274 college students are randomly selected and surveyed, it is found that 123 own a... (answered by stanbon)

When 347 college students are randomly selected and surveyed, it is found that 117 own a... (answered by Boreal)

In a survey of 225 randomly selected gun owners, it was found that 69 of them said they... (answered by Theo)

In a survey of 300 randomly selected gun owners, it was found that 75 of them said they... (answered by Boreal)