Question

Use the following cell phone airport data speeds​ (Mbps) from a particular network. Find Q3

Answer 1

The formula to find quartile 3 is

$\frac{3n}{4}$

Here n = number of observations.

First we need to arrange the bservations in ascending order.

In the table the observations are already in the ascending order.

Now there are 10 observations in each row & there are 5 such rows.

Total number of observations = 5 × 10 = 50

Now

$Q_{3}=\frac{3n}{4}=\frac{3(50)}{4}=37.5$

Now 37.5 lies between 37 & 38th observation

So we shall take the mean of the two.

$Q_{3}=\frac{8.7+8.7}{2}=8.7$

Hence the third quartile is 8.7 Mbps.

Answer 2

The formula to find quartile 3 is 3n/4

Number of observations = n.

Firstly, need to arrange the observations in ascending order.

Now there are 10 observations in each row and there are 5 rows.

Total number of observations = 5 × 10 = 50

Q3 = 3n/4 = 3(50)/4 = 37.5

Therefore, 37.5 lies between 37 & 38th observation

Thus we shall take the mean of the two. Then Q3 = 8.7