Question

Sixty-five randomly selected car salespersons were asked the number of cars they generally sell in one week. Fourteen people answered that they generally sell one car; nineteen generally sell two cars; twelve generally sell three cars; nine generally sell four cars; eleven generally sell five cars. Use this information to calculate the following value. (Enter an exact number as an integer, fraction, or decimal.)

First quartile

Answer 1

Let us construct a frequency table

Cars sold(x)	No. of Salesperson (f)	c.f
1	14	14
2	19	33
3	12	45
4	9	54
5	11	65

here cf : cumulative frequency

We need to find first quartile .

Quartiles divide the data in 4 equal parts

First quartile is the value below which one fourth of the data (x) lies.

Here N= 65 (total number salesperson / observation)

N/4 = 65/4 = 16.5

First quartile is the average of 16th and 17th observation

The cumulative frequency just above 16.5 is 33

Value of x corresponding cf=33 is 2

Thus first quartile = 2