DSE DOUBT

[Sris]

members of the gymkhana club are charged quartely fees on the basis of their avg weight,rounded to the nearest kg.Of d 560 members,120 weighted between 60 and 69 kg, 140 weighted between 70 and 79 kg,170 weighted between 80 and 89 kg,and the remaining weighted between 90 and 99 kg. If members are charged rs 50/kg of their weight, on average how much each member pay?

this is from dse 2006....plz reply

[naren]

avg wt. of 60 to 69 is 65
70 to 79 is 75
80 to 89 is 85
90 to 99 is 95
Total rupees to be paid= 50*(120*65 + 140*75 + 170*85 + 130*95) =2255000
Avg= 2255000/560=4026 ~ 4000

[knowpraveen]

Wrong approach Naren. It has something to do with the distribution and stuff. The explanation you have given is vague and inappropriate or rather, the answer is wrong.

[onionknight]

Nothing wrong with either the approach or the answer, IMO. This is fine.

[Sris]

you know when i take avg weights as 64.5(60+69/2) and 74.5 and so on i get an even closer answer to 4000 as compared to 4026....plz tell me if i am wrong...

[onionknight]

It'll probably be x4.5.

[Sris]

so am i correct?

[onionknight]

Yes, I think so.

[knowpraveen]

The distribution of the numbers have not been given, we can't draw out the average on plain intuition from the given data, its absurd.

[onionknight]

No, it's not. This is how you're supposed to find the mean of a frequency distribution.