The following data is organized from lowest to highest 123 1

The following data is organized from lowest to highest. (123, 125, 127, 141, 149, 185, 203, 215, 234, 234, 252, 279, 302, 303, 321, 327, 350, 358, 404, 425) What is the approximate value of the Third Quartile?

Solution

The following data is organized from lowest to highest. (123, 125, 127, 141, 149, 185, 203, 215, 234, 234, 252, 279, 302, 303, 321, 327, 350, 358, 404, 425) What is the approximate value of the Third Quartile?

There are 20 observations

Q3 is median of the upper half of the data.

Therefore, the upper half of the data is: {252, 279, 302, 303, 321, 327, 350, 358, 404, 425}

Q₃ = (321+327)/2=324

Solution 2

3^rd quartile = 3*(n+1)/4 = 3*21/4 th value

=15.75 the observation

Q3 = 321+0.75(327-321)

=325.5