# Inference from table

• Feb 19th 2011, 06:05 AM
ZOOZ
Inference from table
the Question Description is: Survey Created Among Families about the Their Expenditure In a week.
in the picture you can see the Information.

1) Question i asked to find the Expenditure Median.
A)500$B)510.66$
C)516.66$D)650$
I know for example the if i got Series of number like 1,2,22,7,19,8 we got here 6 numbers so 7 will be the Median but in my Question i not find any Median from the answers that given.

Attachment 20867
2)i asked to find the Average Expenditure.
A)514
B)528
C)542
D)556
i know to find the Average for example: 1,2,5,7,9 is will be 1+2+5+7+9=24/5
hope you can help me.
thanks.
• Feb 19th 2011, 12:58 PM
pickslides
I can help here.

Because you have a table with a range of values each families expenditure could be you should take the midpoint of each for your calcs. Yuo have 30 families with expenditure from 0-200 so lets give them all \$100 as an indicative value.

For the median imagine putting these figures in a line like you usaully would. 100, 100, 100, ...(there are 30 of these!) ...,300, 300, 300 (there are 40 of these!) and so on. This is a terrible job and no one should do it, but the workaround is very simple. Simply add the number of families column together, you get 270? Halfway like the Median suggests would be in between the 135th and 136th number. Now go through that column again finding where this value would live. Once you are there the corresponding right hand column will your answer.

For the mean, using the same idea as just explained it should now be obvious that
$\displaystyle \bar{x} =\frac{30 \times 100 +40\times 300 + \cdots +40\times 900}{30+40+\cdots +90}$
• Feb 20th 2011, 01:26 AM
ZOOZ
hi. thanks for your answer i found that the mean is 528.

but about the First Question, i add the number of families column together and i got 250 so Halfway like the MEdian suggests would be between the 125th,126th,so i go through that column again and i found where this value would live (where is the 90 Families ) so the right hand column there show 500-800 so i did 500+800/2=650 and this is the MEdian ?
thank you.
• Feb 20th 2011, 01:05 PM
pickslides
I think you have the idea~!