SOLUTION: Hi, I'm stuck with this question, please help me :( An economist wishes to estimate the average family income in a certain population. The population standard deviation is known t

Question 446013: Hi, I'm stuck with this question, please help me :(
An economist wishes to estimate the average family income in a certain population. The population standard deviation is known to be $4,500 ; and the economist uses a random sample of size n=225. What is the probability that the sample mean will fall within $800 of the population mean?
Thanks you !
Answer by ewatrrr(24785) (Show Source): You can put this solution on YOUR website!

 

Hi,

*Note: 

  = 800 , n = 225 and 

    z = 800/4500/15 =  800/300 = 2.6667  P(z < 2.6667 = .9962

And z = -800/300 = -2.6667  P(z < -2.667) = .0038

 P( -2.667 > z < 2.6667) = .9962-.0038 = .9924 

RELATED QUESTIONS

i have two questions i have been working on for a week please help

 
question 1... (answered by solver91311)
Hi, I have been trying to solve this question but it proves to be a hard nut to crack.... (answered by ankor@dixie-net.com)
The following information refers to the next four questions:
An insurance company wishes  (answered by ewatrrr)
an economist claims that the mean family income of a certain populated area in metro... (answered by Theo)
To me, this looks like a question not to hard to solve, but yet I am stuck on it. It... (answered by stanbon)
An insurance company wishes to examine the relationship between income (in $,000) and the  (answered by stanbon)
An economist for a certain car manufacturing process indicates that a car manufacturing... (answered by ikleyn)
An economist for a certain car manufacturing process indicates that a car manufacturing... (answered by Theo)
you see i am a high school student and i am stuck in this question. Determine the measure  (answered by nomad_55)