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x, 6, 18, 21, 27, 27

If the average (arithmetic mean), median, and unique mode of the six integers shown above, when arranged in increasing order, are consecutive multiples of 3, what is the range of all possible values of x?

A. 27
B. 54
C. 57
D. 81
E. 108

average of given sequence is
x+6+18+21+27+27 /6 ; 99+x/6
avg, median , mode all have to multiple of consecutive multiples of 3
test with values of x in

(99+x) / 6 ; the value has to be such that it is multiple of 3 and is twice divisible
smallest value of x will be 27

99+27 = 126 ; avg is 21
6,18,21,27,27,27

avg 21
median 24 mode is 27
(21, 24,27)


and largest value of x will be at 81
99+81 = 180 ; avg 30


6,18,21,27,27,81

avg 30 , median is 24 mode is 27 ( 24,27,30)

range of value of x 81-27 =54

OPTION B is correct
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Mode = 27

Median = 3rd and 4th no

if x<21 median =19.5
if 21<x<27 median = 21+x /2 (fraction)
thus x > 27
gives: median = 21+27/2 = 24

Consecutive multiple of 3
median = 24, mode =27 mean either 21 or 30

Sum of without x = 99
Make cases:
I. Mean = 21
99+x / 6 = 21
x = 27

II. Mean = 30
99+x / 6 = 30
x = 81

Possible values of x 27/81
range = 81-27 = 54
Answer: B
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I selected B - 54.

Focusing on the constraints in the problem, notice that the mode must be unique. Since we only have one unknown in the set, the mode must be equal to 27.

If the mode is 27, and the mean, median and mode are consecutive multiples of 27, that limits the possible values of the mean, median and mode to a set of 3 consecutive integers from the following: 21, 24, 27, 30, 33.

Let's investigate the potential values for the median. If x is greater than or equal to 27, the median will be equal to 24. That means the mean must be equal to 30 or 21. Take mean = 30 to find the maximum value of x. That yields the equation 99 + x = 6(30), or x = 81. Take this as the maximum for x.

Looking at the minimum value of the median, if we make x less than or equal to 21, the median will not be an integer, which means the minimum value of the median must be 24. Therefore, the mean must be 21 in this case.

Take 99 + x = 6(21), which yields x = 27. This must be the minimum value of x.

81 - 27 = 54, answer B.
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From my understanding
The mode will be unique, therefore, we cannot bring x = 21 again here.
Since if we arrange mean, median, and mode, it would be consecutive multiples of 3. (increasing order)
median = (21+27)/2 = 48/2 = 24
Mode = 27
Therefore mean can be 21, median 24, and mode 27.
Hence, mean = (6+18+21+27+27+x)/6 = 21
mean = x + 99 = 21*6 = 126
or x = 27

Another possibility could be, mean = 30, mode = 27, median = 24, those are multiples of 3.
In that case, x = 30*6 - 99 = 81

Therefore, the range of all possible values for x = 81 - 27 = 54
Answer: B
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trying options unique mode comes as 27. ( most repeated nmber in the dataset. )
mean will be (6+18+21+27+27+28)/6 = 126/6 = 24
meadian of dataset is 21+27 / 4 = 24

answer A 27
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Given mode is unique it has to be 27, so x cant be 6, 18, 21.

Lets try x = 27,

21, 24, 27 / 24, 27, 30 / 27, 30, 33

6+18+21+27+27+ x = 99 + x / 6, x = 21, gives average 27 so incorrect, x = 24 gives average x = 45 so wrong, x = 27, average = 21 works, median = 24 works.

X = 27

next x > 27

mode = 27 ; median = 24; mean = 30 , x is 84

84-27 = 54
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x, 6, 18, 21, 27, 27

Mean = (x+6+18+21+27+27)/6 = (x+99)/6
Median = (x + 21)/2 or (21+27)/2= 24; Since (18+21)/2 is NOT an integer.
Mode = 27

Mode = 27 is one multiple of 3;

{21,24,27}: x= 27; Mean = 21; Median = 24; Mode = 27
{24,27,30}: Mode =27; Median = 24; (x+99)/6 = 30; x=81
{27,30,33}: Mode =27; (x+21)/2 = 30; x = 39; (39+99)/6 is NOT an integer; (x+21)/2=33; x = 45; (45+99)/6 = 24; Not feasible

Range of all possible values of x = 81 - 27 = 54

IMO B
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i am going with option b.
unique mode: 27
median: sorting known terms shows that when x is greater than or equal to 27, 2 middle numbers 21 and 27 makes the median 24.
mean: either be 21 or 30 to create a sequence of consecutive multiples of 3.
max - min = 81-27 = 54
a incorrect - if you solve only for min value and mistake that single value for final range.
c and e incorrect - occurs if include invalid values for x.
d incorrect - occurs if you find max value and forget to subtract min value to get the range
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Answer: B) 54

Not sure about this one but I'll share my reasoning.

No matter what the value of x is, the highest mode is 27 (if x is one of the other values, then the sequence is bimodial so I'm guessing we'd only consider the larger mode as we are ask to sort it from smallest to largest).

There are three possible scenarios:
1 & 2. Mode is the highest (which means the median is 24 and the mean is 21 or vice versa)
3. Mode is the second highest (which means the median is 24 and the mean is 30)
- > The median can't be higher than 27 as the median of an even amount of data is the midpoint between the two middle values

Scenario 1:
Mode is 27, Mean is 24, Median is 21
(x + 6 + 18 + 21 + 27 + 27)/6 = 24, x = 45
Median = (21 + 27) / 2 = 24, doesn't work

Scenario 2:
Mode is 27, Mean is 21, Median is 24
(x + 6 + 18 + 21 + 27 + 27)/6 = 21, x = 27
Median = (21 + 27) / 2 = 24, works

Scenario 3
Mode is 27, Mean is 30, Median is 24
(x + 6 + 18 + 21 + 27 + 27) / 6 = 30, x = 81
Median = (21 + 27) / 2 = 24, works

Range of possible values = 81 - 27 = 54
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There are already two occurrences of 27, and only one unknown value x. So we know 27 is the mode.

If x>=27, the ordered list would be 6,18,21,27,27,x. Then median is 21+27/2 = 24
If x=21, there will be two modes. Not possible.
If x<21, median will not be a multiple of 3 as there are even number of integers.

So mode is 27, median is 24.

In this case mean can be either 21 or 30.

6+18+21+27+27=99

If mean is 21,
(x + 99) / 6 = 21
x=27

If mean is 30,
(x + 99)/ 6 = 30
x = 81

Then range of possible values of x = 81-27 = 54

Therefore 54 is the answer.

Bunuel
x, 6, 18, 21, 27, 27

If the average (arithmetic mean), median, and unique mode of the six integers shown above, when arranged in increasing order, are consecutive multiples of 3, what is the range of all possible values of x?

A. 27
B. 54
C. 57
D. 81
E. 108


 


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So the wording of the question has to be closely looked into and checked over when answering the question:

What it says is that the arithmetic mean (average), median and unique mode of the six integers when increased in ascending order are consecutive multiples of three.

The word unique mode is significant. This means 'x' cannot be a value which gives rise to two modes. From the problem set, 27 repeats twice. So this means that 'x' was any other number in the problem set, i.e., say 21 then that would give two modes, 21 and 27 which is impermissible.

So we have 27 as the unique mode.

Next we know that:
Mean , Median , Mode when arranged are in consecutive multiples of 3. This is the next keyword.

Hence, the Mean will be 21, Median and 27. Median of this set is 21 + 27 /2 = 48/2 = 24. Hence the Median is 24.

The range is the highest value minus the lowest. The Mean / Average of all six numbers is 21... Hence 21 X 6 = 126

Therefore, Sum of All / 6 = 126

6 + 18 + 21 + 27 + 27 + x = 126
99 + x = 126 Hence x = 27

Hence, the only value which is applicable in this set is 27. Hence the answer is (A).
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x , 6, 18, 21, 27 , 27

Mode:
as of now, Mode is 27, if x is 6, 18 or 21, the mode might change
as question says unique mode, X cannot be 6, 18 or 21, which gives one value 27

Median:
lets write cases is X<6, median = (18+21)/2 = 19.5 not a multiple of 3
similarly, if 6<x<18, median again is 19.5, not good
18<x<21 - median (x+21)/2 - not sure
and 21<x<27, median = (21+x)/2 - not sure
for x>27, Median = (21+27)/2 = 24 valid

the median should fall from 19.5 to 24 within this only 21 and 24 are accepted median values, but for (x+21)/2 = 21, x should be 21, which will break the Unique mode concept, so Median is 24

mean:
X+99/6

but we have Median as 24, and Mode as 27,

so possible consecutive 3 multiples is either 24,27,30 or 21,24,27
meaning mean is either 30 or 21
equating - 21 * 6 = x+99 ----> x = 27
and 30*6 - 99 = x ------> x = 81

Range is 81 - 27 = 54
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As per the question stem, x could be any integer (positive, negative and zero)the numbers have unique mode.


i.e. x could not be any of the 6,18,21,27. And the Mode is 27.
As per the question stem, Mean, Mode and Median as consecutive multiples of 3 i.e. have difference of 3's multiple.
Hence, Mean and median should be somewhere around 27. Mean and median should be any of 21,24,27,30,33 (numbers with difference 3)

If 18<x<21 then Median = (x+21/2) which should be integer. Possible values are x = 19. Not possible
If 27<x then median = (21+27)/2 = 24. Possible. Median = 24

Now based on above information, after getting Mode and Median, probable values of mean are 21, 30. Let's check these two numbers whether they are compatible with mean equation shown below.

Mean = (x +6+18+21+27+27)/6 = (99+x)/6

If Mean = 21 then x = 21*6-99 = 27
If Mean = 30 then x = 30*6-99 = 81

Range of all possible values of x = 81-27 =54
Bunuel
x, 6, 18, 21, 27, 27

If the average (arithmetic mean), median, and unique mode of the six integers shown above, when arranged in increasing order, are consecutive multiples of 3, what is the range of all possible values of x?

A. 27
B. 54
C. 57
D. 81
E. 108


 


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mode=27
cons multiple=21,24,27

so median 24, mean 21

median=18+21/2
19.5<x<27

mean=x+99/6=21
x=27

thus, 18<x<=27
smallest int=19, largest=27

range=8
to find all poss value of x
x<6
mean =18
x+99/6=18
x=9
finally value becomes 9<=x<=90
range =90-9=81
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The correct answer is 54. B.

For the mode: x,6,18,21,27,27.
Here the unique mode is 27 as it appears twice.

For the median, there are 6 numbers; hence, the average of the 3rd and the 4th term will be the median.

Case 1: x<21, then the numbers would be 18 and 21
(18+21)/2= 19.5 (this is not a multiple of 3)

Case 2: x>27 then the numbers would be 21 and 27.
(21+27)/2= 24 (multiple of 3)

Hence, the median is 24.

As all three, mode, median and mean are 3 consecutive multiple of 3, there are 2 cases:
Set A: 21,24,27- here the average =21, median =24, mode=27
Set B: 24,27,30 - average=30, median=24, mode=27


All the possible value of x,
Average= (x+6+18+21+27+27)/6 = (x+99)/6

Considering from above,
Case 1, average= 21
(x+99)/6=21
x+99= 126
x=27

Case 2, average =30
(x+99)/6=30
x+99=180
x=81

So, the range of x= 81-27= 54.
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x, 6, 18, 21, 27, 27

Unique Mode must be 27.
Mean = (x+6+18+21+27+27)/6= (x+99)/6
Median depends on value of x.
If x<18, Median= 18+21/2= 19.5
x can't be 21. Or Unique value of mode will be gone.
If x≥27, Median= 21+27/2= 24
Only valid value of Median is 24.
Mean, Median, Mode are all multiples of 3.
Mean, Median, Mode can be (21,24,27) or (24,27,30)
If Mean= 21, x+99=126 ; x= 27
If Mean= 30, x+99=190 ; x=81

Possible range for x= 81-27= 54

B
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MODE is 27 as it appear twice unless x is 27 then it appear three times

If x<= 18. The median is 18 + 21 /2 = 19.5. Not a multiple of three. therefor x can not be less than or equal to 18

If 18<x<=21. The medican is x+21/2 = multiple of 3. Only value that works is 21. Does not work because than there would be two modes 21 and 27

If x >=21. Than middle numbers are 21

If 21<x<=27
Sort 6, 18, 21, 27, 27, 27

Mean is 6+18+21+27+27+27/6 +21
Median 21+27/2 =24
mode = 27

If x>27
middle elements are 21 and 27
median 21+27/2=24
Mode 27
Mean 6+18+21+27+27+x/6 = 99 +x/6

For a sequence of multiples of 3. Than 24, 27 and 30.

99+x / 6 = 30
99 + x = 180
x = 81

6, 18, 21, 27, 27, 81
mean = 30
median = 24
mode = 27

Possible values for x 27 and 81

range is 81 - 27 = 54

Answer B 54
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