homework help please: normal distribution has mean=310 and third quartile =391. X=49

[kbunny21]

Problem A-a normal distribution has mean=310 and third quartile =391. X=490. Find the z-value

Problem B-mean=183.5 and standard deviation=31.2, find the data value corresponding to z-value 0 and -1.

I've been working on these for 3 days, looking at youtube tutorials, I have no idea what to even call it. Please help. I have a test on Monday.

 

[Steven G]

Problem A-a normal distribution has mean=310 and third quartile =391. X=490. Find the z-value

Problem B-mean=183.5 and standard deviation=31.2, find the data value corresponding to z-value 0 and -1.

I've been working on these for 3 days, looking at youtube tutorials, I have no idea what to even call it. Please help. I have a test on Monday.

What have you tried? Exactly where are you stuck? Can you state the formula for the z-score?

 

[mmm4444bot]

I've been working on these [two exercises] for 3 days …

Please show us one of your attempts.

Also, be sure to read the forum guidelines. Here's a summary. Thank you! :cool:

 

[HallsofIvy]

You will need to use a table of the standard normal distribution. There is probably one in your text book but there is one at http://math.arizona.edu/~rsims/ma464/standardnormaltable.pdf.