Question about expected frequencies

[chuy52506]

Say I have ranges:
(-infinity to 16) where the observed frequency is 35
(16 to 18) where the obs freq is 100
(18 to 20) where the obs.. freq. is 360
(20 to 22) where the obs. freq. is 326
(22 to 24) where the obs. freq. is 150
(24 to infinity) where the obs freq is 29

The mean is 20 and standard deviation is 2

How would i find the expected value of each range?

 

[mathman]

You really can't. For all except the end ranges a good estimate is the midpoint. For the two ends there is not much you can do.

 

[chuy52506]

sorry i meant to ask how do you find the expected frequency not value?

 

[mathman]

sorry i meant to ask how do you find the expected frequency not value?

The best estimate for the expected frequency is the observed frequency.