Question

If we assume the average number of teeth lost in the 5-9 group is 7 teeth and the average number of teeth lost in the 10 group is 12 teeth, what is the best estimate of the average (mean) and variance number of teeth lost per year

Answer 1

Average = 7.83

Variance = 20.8339

Explanation:

Since the average number of teeth lost in years 5-9 was 7 teeth this means that the average was 7 each year. Therefore, to estimate the average of teeth lost per year including all the years then we need to add the average each year and divide by the number of years being included like so...

7 + 7 + 7 + 7 + 7 + 12 = 47 teeth

47 teeth / 6 days = 7.83

Now that we have the mean we can find the variance.

`(7-7.83)^(2)` = 0.6889

`(12 - 7.83)^(2)` = 17.3889

0.6889 + 0.6889 + 0.6889 + 0.6889 + 0.6889 + 17.3889 = 20.8339