Respuesta :

Answer:

[tex] IQR =Q_3 -Q_1[/tex]

We have for this case n= 8 values. In order to find the Q1 we can select the first 4 values {33, 38, 45, 56 and the Q1 would be:

[tex] Q_1 = \frac{38+45}{2}= 41.5[/tex]

And for the Q3 we can select the last 4 values 57, 63, 72, 91 and for Q3 we got:

[tex] Q_3= \frac{63+72}{2}= 67.5[/tex]

And then the interquartile range would be:

[tex] IQR =Q_3 -Q_1 = 67.5-41.5 = 26[/tex]

Step-by-step explanation:

For this problem we have the following dataset ordered:

{33, 38, 45, 56, 57, 63, 72, 91}

And we want to find the interquartile range defined as:

[tex] IQR =Q_3 -Q_1[/tex]

We have for this case n= 8 values. In order to find the Q1 we can select the first 4 values {33, 38, 45, 56 and the Q1 would be:

[tex] Q_1 = \frac{38+45}{2}= 41.5[/tex]

And for the Q3 we can select the last 4 values 57, 63, 72, 91 and for Q3 we got:

[tex] Q_3= \frac{63+72}{2}= 67.5[/tex]

And then the interquartile range would be:

[tex] IQR =Q_3 -Q_1 = 67.5-41.5 = 26[/tex]

The correct answer is:

26

I took the test, hope this helps!