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 as of September 2010. Calculate the estimated mean age in years for my friends by calculating ∑ x * p(x). Use the class upper limits. Use seven bins. Ignore the 338 friends who did not list their age. Use 55 years old as the class upper limit for the last class (45 years and older).
| Age classes x | Frequency (f) | Relative Frequency p(x) | x * p(x) |
|---|---|---|---|
| Sums: |