# Thread: Can someone check my box and whisker plot for me

1. ## Can someone check my box and whisker plot for me

I haven't made one in a long time and just want to make sure it's correct. The .pdf is the actual graph I made. It's not to scale or anything. I'm more interested in whether the numbers are correct. The .pdf file is the data set and how I calculated the numbers. If someone knows a way of creating a box and whisker plot using Excel, I'd love to learn how. I've tried looking online in the past but haven't really found anything.

I didn't label it but there are fifty values in the data set.

2. Hi

I have not checked you answers yet, but in the mean time I hope this may help you.

3. Hi

I seem to get slightly different answers to you.

4. Sorry that it's taken me so long to respond. I should have posted the manner in which I got all of my numbers. Anyway, here goes:

$Q_{1}=0.25(50)=12.5=$13th value in the ordered data set=7
$Q_{2}(median)=0.5(50)=25=25th$ value in the ordered data set=10
$Q_{3}=0.75(50)=37.5=$38th value in the ordered data set=16[/tex] (I messed up on this one)

Now, for the upper and lower whiskers, I was taught to take the interquartile range (IQR) $Q_{3}-Q_{1}$, multiply it by 1.5 and then add the product to the $Q_{3}$ to find the upper whisker and subtract the product from [tex]Q_{1} to find the lower whisker. So that would be:

$IQR=Q_{3}-Q_{1}=16-7=9$
$Lower Whisker=Q_{1}-1.5(IQR)=-5.65$ But since the lowest value in the data set is 3, 3 becomes our lower whisker. I screwed up on that too.
$Upper Whisker=Q_{3}+1.5(IQR)=29.5$Upper whisker is 29.5. There is one value (32) higher than the upper whisker. That value is an outlier.