Posting on Behalf of a 7Sage User: PT1.S3.Q7 - A population of game ducks

Diana - Student Service

[I am posting on behalf of a 7Sage user:]

Can you go through and explain I am really confused I think PT 1 S3 Q07 has answer mistake.

The last sentence says that there is more male duck in the old duck ration compared to young duck ration with the female duck, which means more male in OD: FD compared to YD:FD.
After stating that they are saying that NOW we can infer that if there is more disparity b/w two sexes M: F the more the adult male ducks will be.
it is like saying that there are two liquids A AND B in both A and B there are three components 1,2, 4
( 1,2 both belong to the same group so lets say 1+2=3 )
now they have given us a ratio of 3:4 for both A and B and said that 3 is more in quantity than 4
but we know 3 has two components 1, 2 and they have also given us quantity comparison of 1,2,4 they are saying 1 has less quantity gap with 4 means if we add 1 into one flask and 4 into another flask they will look filled nearly the same, but if we compare 2 and 4 in quantity 2 is much more than 4
now they are saying we can use this for all so whenever 3 increases 2 will increase in greater proportion than 1 because the ratio of 2 is more compared to 4 means there are many 2 compared to 4 than there are 1 compared to 4,
A/B= west/east
1=young male 2 =old male 3=1+2 (all male)
4= total female

henry.ewing

Hey there! Here is a quick breakdown

western lake is 55% male and 45% female
eastern lake is 65% male and 35% female.

The last claim of the stimulus says that larger the disparity between sexes, the greater the percentage of adult male ducks.

Who has a larger disparity between sexes? Eastern lake! So we know that eastern lake has a larger percentage of adult males than western lake.

Answer Choice A reflects this inference.

I'm guessing you think there is an error in Answer Choice C. There is not. Answer choice C says that there the -actual- number of male ducks in eastern lake is greater than the actual number of male ducks in western lake. The problem is that we do not know how many ducks are in each lake, we only know the ratio of male to female ducks.

Dastin Kartoum

Answer Selection Breakdown

A, The ratio of male to total ducks at Western Lake is less than the total ratio of male ducks to total ducks at Eastern Lake.

Eastern Lake

65 Males per 100 Ducks

Western Lake

55 Male per 100 Ducks

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B. Non-adult ducks make up a greater portion of the population of total ducks at Eastern than Western.

This could be true but we have limited information on the total of non-adult ducks. However we do know that there is a small disparity between sexes in non-adults which with the limited data that is presented we could infer that Western Lake has a greater percentage since the ratio of Male to Female is in greater proportion.

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C. This is another could be true. The issue with answer choice C is that we do not know the total number of ducks we only know the ratio which could be applied to any number of ducks.

Example both lakes contain 100 Ducks

Eastern

65 male

35 female

Western

55 male

45 female

Example 2

Eastern lake contains 500 total ducks and Western Lake contains 700 Total Ducks

Eastern

325 Males

175 Females

Western

385 Males

315 Femals

Because of this, the statement that there are more male ducks in Eastern Lake Vs. Western Lake does not hold true in all circumstances.

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D, The ratio of male to female is closer to 1:1 in non-adult ducks. If this is to be true then then the ratio of male to female must be decreased, However we know that non-adult ducks can not drastically affect the population distribution among sexes because we know from the stimulus that male ducks significantly outweigh non-adult male ducks.

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E. Since male ducks greatly outweigh the number of non-adult male ducks and that non-adult male ducks outnumber non-adult female ducks we can infer that Adult female ducks outnumber non-adult female ducks.

Y----patel

But let’s say old/adult 48 male to 40 female and
young/not old 7 male to 5 female
so total 55 male to 45 females
and let’s say internal ratios are same, in both west lake and east lake, for convenience means old male to old female ratio 48to40 =1.2:1
And young male to young female 7to5=1.4:1 so we can apply these ratios to east lake
So we have assumed same internal ratios for both lake that is for every 48 male old ducks 7 young male duck and 40:5 for old females to young females
Now we get 48+7=65 bez internal ratios are same so by solving all equations like that we get _56.72 old male to 20 old female and
47.27 young male to 14 young female (( ratios are not quite adding up for significant and less proportion of many more male old compared to less more young male for comparative females but some math guy can get ratios for that in infinite series of numbers)
So now you can see we can infer answer A but with same perspective we can also infer B. thank you Diana for posting my query. Sage tell me where am I going wrong here dastinpixel also suggesting nearly same thing.
And we don’t know actual numbers that is why I assumed internal ratios are same.