Distribution help

[VANcity]

Hi, help with any of these is greatly appreciated.


n=sample, p= probability x = random sample from n
how to find:
the chance that x is neither a success nor a failure
the chance that at least x neither succeed nor fail.


also, from sampling distributions,
according to the Bureau of Labour statistics, the average weekl pay for a production worker in a certain city was 440$ in '07. assume normal distribution with a standard deviation of 90$.

a)what is the chance that a worker earns between 400 and 500?

I think I was able to solve this like this:
z=(500-400)/90 = .66 using z table area = .7454
z=(400-440)/90 = .44 area= .33
.7454-.33=.4154
41.54%chance

These are the ones I need help with:

b)How much does a production worker need to earn so that he can be in the top 10% of wages?

c)For a random selected production worker, what is the chance the worker earns less than $250 per week?
what formula should I use to find these?
Thanks

[vinux]

Hi, help with any of these is greatly appreciated.


n=sample, p= probability x = random sample from n
how to find:
the chance that x is neither a success nor a failure
the chance that at least x neither succeed nor fail.

This question is incomplete. What is the definition of success here?
or what is p ? ( what probablity)