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iamba
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are both sets of number in order? or random?

if they are not in order than i think it cannot be determined

if they ARE indeed in order then

difference in range = [(A9+9)-(A1+1)] - (A9-A1) = 8
difference in mean = (sumA+45)/9 - sumA/9 = 5

got 13 as well (8+5)
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OA is E

OE says that the set A can have the numbers in either ascending or descending order
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Set A is composed of nine numbers, labeled A1 through A9. Set B is also composed of nine numbers, labeled B1 through B9. Set B is defined as follows: B1 = 1 + A1; B2 = 2 + A2; and so on, including B9 = 9 + A9. How much larger is the sum of set B's mean and range than the sum of set A's mean and range?
A 4
B 9
C 13
D 17
E Cannot be determined
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I got C,

the diffrence between mean of mean B's and mean A's is 5, and the difference between ranges is 8 in total it is thirteen.

Ans: C
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ashkrs
Set A is composed of nine numbers, labeled A1 through A9. Set B is also composed of nine numbers, labeled B1 through B9. Set B is defined as follows: B1 = 1 + A1; B2 = 2 + A2; and so on, including B9 = 9 + A9. How much larger is the sum of set B's mean and range than the sum of set A's mean and range?
A 4
B 9
C 13
D 17
E Cannot be determined


Given:
Sum of Set A = Sa
Sum of set B = 1+A1+2+A2 + ... + 9+A9
= 1+2+3+4+5+6+7+8+9+Sa
= 45 + Sa

Want to find:
Ans = (Mb + Rb) - (Ma + Ra) = Mb - Ma + Rb - Ra
Know:
Mb = (45 + Sa)/9 = 5 + Sa/9
Ma = Sa / 9
Rb = (A9+9) - (A1+1) = A9-A1 + 8
Ra = A9 - A1

Ans = 5 + Sa/9 - Sa/9 + A9 - A1 + 8 - A9 + A1 = 5+8 = 13
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ashkrs
Set A is composed of nine numbers, labeled A1 through A9. Set B is also composed of nine numbers, labeled B1 through B9. Set B is defined as follows: B1 = 1 + A1; B2 = 2 + A2; and so on, including B9 = 9 + A9. How much larger is the sum of set B's mean and range than the sum of set A's mean and range?
A 4
B 9
C 13
D 17
E Cannot be determined


C.

Plugged in numbers 0 through 8 in set A. Worked out numbers for set B according to the formula in the stem. Got answer C.
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I got C too . But thats not the OA .
Its actually E .
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ashkrs
I got C too . But thats not the OA .
Its actually E .


We don't know whether A1 is the smallest or largest element in A- if it is the smallest, the range of B will be higher, but if it is the greatest, the range of B may be lower
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kevincan
ashkrs
I got C too . But thats not the OA .
Its actually E .

We don't know whether A1 is the smallest or largest element in A- if it is the smallest, the range of B will be higher, but if it is the greatest, the range of B may be lower


Can you explain further?
In my opinion, I don't think it matters since all the terms cancel out anyways.
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bkk145
kevincan
ashkrs
I got C too . But thats not the OA .
Its actually E .

We don't know whether A1 is the smallest or largest element in A- if it is the smallest, the range of B will be higher, but if it is the greatest, the range of B may be lower

Can you explain further?
In my opinion, I don't think it matters since all the terms cancel out anyways.


Consider Ak=k vs Ak= 9-k for all positive integer k < 10



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