what is the best estimate

Question

The table below gives the percent of children under five considered to be underweight.

Percent of Underweight Children Number of Countries

16–21.45 23

21.45–26.9 3

26.9–32.35 8

32.35–37.8 6

37.8–43.25 7

43.25–48.7 2

What is the best estimate for the mean percentage of underweight children? (Round your answer to two decimal places.)

_______

Answer 1

Nathan

Take the midpoint of each range as representing the data points in the range.

So for first range midpoint = (16 + 21.45) / 2 = 18.725

So you can assume you have 23 data points , all 18.725

Do the same for all the other ranges

Suppose the other midpoints are m2, m3, m4. m5. m6

Then your mean = total of estimated numbers / number of numbers =

(18.725 x 23 + 3 m2 + 8 m3 + 6 m4 + 7 m5 + 2 m6 ) / (23 + 3 + 8 + 6 + 7 + 2)

Mike