SOLUTION: A survey of 800 women shoppers found that 17% of them shop on impulse. What is the 98% confidence interval for the true proportion of women shoppers who shop on impulse? A. 0.136

Question 1040399: A survey of 800 women shoppers found that 17% of them shop on impulse. What is the 98% confidence interval for the true proportion of women shoppers who shop on impulse?
A. 0.136 < p < 0.204
B. 0.139 < p < 0.201
C. 0.148 < p < 0.192
D. 0.144 < p < 0.196
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!

Use this table (or similar) to find that the critical z value is 2.326

Look at the confidence level of 98% (bottom of page). Then look directly above it to find the value 2.326

So z = 2.326

-----------------------------------------------------------------

Given information
phat = 0.17
n = 800

Standard Error:
SE = sqrt(phat*(1-phat)/n)
SE = sqrt(0.17*(1-0.17)/800)
SE = 0.0132806249853

Margin of error
ME = z*SE
ME = 2.326*0.0132806249853
ME = 0.0308907337158

Lower Bound (L) of the confidence interval
L = phat - ME
L = 0.17 - 0.0308907337158
L = 0.1391092662842
L = 0.139

Upper Bound (U) of the confidence interval
U = phat + ME
U = 0.17 + 0.0308907337158
U = 0.2008907337158
U = 0.201

The confidence interal is (L,U) = (0.139, 0.201) which is equilavent to saying L < p < U which turns into 0.139 < p < 0.201

So the answer is choice B) 0.139 < p < 0.201

The population proportion p is somewhere between 13.9% and 20.1% and we're 98% confident of this fact.

RELATED QUESTIONS
1) A recent study of 750 internet users in Europe found that 260 of internet users were... (answered by stanbon,edjones)

A survey of 750 women found that 135 of them shop on impulse. What is the 90% confidence... (answered by Alan3354)

A recent study of 750 Internet users in Europe found that 35% of Internet users were... (answered by stanbon)

In 2009, a consulting firm surveyed a random sample of 700 U.S. businesses and found that (answered by stanbon)

6. Each day a quality engineer selects a random sample of 100 bolts from the day�s... (answered by solver91311)

please help me solve this question. a random sample of 40 shoppers showed that they... (answered by Theo)

In a simple random sample of 1300 full-time students at a large university, it is found... (answered by Boreal)

Can you please tell me if this is correct? If one of the 50 shoppers surveyed is chosen (answered by stanbon)

I need some serious help please! Find the appropriate confidence interval for the... (answered by stanbon)