## anonymous 5 years ago Does anyone know how to find Q1,IRQ,Q3??

1. anonymous

Q1 = 25% or pop IQR = Q3-Q1 = 50% Q3 = 75%

2. anonymous

My data is 30,35,20,25,42,32,3,20,35

3. anonymous

how do i do that

4. anonymous

$Q1 = \frac{1}{4}(n+1)\text{ Where n is the number of data values }$ so we have n = 9 $\frac{1}{4}(9+1) = \text{2.5 th value}$ so take the average of the second and third values {3, 20, 20, 25, 30, 32, 35, 35, 42} $Q1 = \frac{20+20}{2}=20$

5. anonymous

$Q_3 = \frac{3}{4}(n+1)$ $Q_3 = \frac{3}{4}(10) = 7.5 \text{ th value }$ so take the average of the 7th and 8th values of {3, 20, 20, 25, 30, 32, 35, 35, 42} $Q_3 = \frac{35+35}{2}=35$ The interquatile Range $IQR = Q_3-Q_1 = 35-20 = 15$

6. anonymous

Or you could do 7.5-2.5 = 5 so your 5th value in {3, 20, 20, 25, 30, 32, 35, 35, 42} divided by 2 = 30/2 = 15

7. anonymous

$\text{IQR = } \text{Q}_3-\text{Q}_2 = 35-20 = 15$