The image above is from a FaceBook application called Friend Statistics. The image provides a histogram of the distribution of the ages of my friends on FaceBook. Calculate the estimated mean age in years for my friends by calculating ∑ x * p(x). Like many statistical situations in the "real world" the data does not come all pre-digested and ready to calculate. You must decide what to use for the classes. Suggestions: Use seven bins. Ignore the 144 friends who did not list their age. You decide how to handle the last class 45 years and older.
|Age classes x||Frequency (f)||Relative Frequency p(x)||x * p(x)|
The mean age is: