Statistics problem

[rure]

A dean must distribute salary raised to her faculty for next year. She has decided that the mean raise is £2500 and the standard deviation is £425 and the distribution is to be normal.

The most productive 10% of the faculty will havea raise equal to or greater than £____

The worst 5% will recieve no more than £_____ each

Help me please

 

[Escape]

The standard deviation is how much she pockets before distributing the rest, right?

 

[rure]

The standard deviation is how much she pockets before distributing the rest, right?

no thats the mean raise xD

 

[yaruar]

A dean must distribute salary raised to her faculty for next year. She has decided that the mean raise is £2500 and the standard deviation is £425 and the distribution is to be normal.

The most productive 10% of the faculty will havea raise equal to or greater than £____

The worst 5% will recieve no more than £_____ each

Help me please

most productive = 3199

worst = 1667

based around the confidence intervals of a normal distribution. Although it's been far too long since i did the stats part of my degree to work it out properly and i did cheat and look up the confidence intervals.

 

[rure]

most productive = 3199

worst = 1667

based around the confidence intervals of a normal distribution. Although it's been far too long since i did the stats part of my degree to work it out properly and i did cheat and look up the confidence intervals.

Thanks but I managed to solve it. I did like you did in the beginning. After looking up confidence intervals and checking the z-value for the 10% best I multiplied that value with the standard deviation and added the mean raise.