Question

The following box plots show how many hours fifth-grade students and seventh-grade students studied in a given month.


If their interquatile range are $I_1$ and $I_2$ respectively, then

• A. $I_1>I_2$
• B. $I_1<I_2$
• C. $I_1=I_2$
• D. None of the above

Answer 1

The correct option is C $I_1=I_2$

The inter-quartile range of a data set is the difference of the upper quartile and the lower quartile.

$5^{th}$ grade students:

$\text{Upper quartile}=70,\text{lower quartile}=30$
$\text{Inter-quartile range}\left(I_1\right)=70-30=40$

$7^{th}$ grade students:

$\text{Upper quartile}=100,\text{lower quartile}=60$
$\text{Inter-quartile range}\left(I_2\right)=100-60=40$
$\therefore I_1=I_2$

Option (c.) is the correct choice.