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The average (arithmetic mean) of the five numbers x, 91, 120, 134, and
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Updated on: 30 Jul 2018, 01:40
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The average (arithmetic mean) of the five numbers x, 91, 120, 134, and 220 is what percent of the sum of the five numbers? (A) 20% (B) 22% (C) 25% (D) 30% (E) It cannot be determined from the information given.
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Originally posted by bettatantalo on 30 Jul 2018, 01:24.
Last edited by Bunuel on 30 Jul 2018, 01:40, edited 1 time in total.
Renamed the topic, edited the question, added the OA and moved to PS forum.



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Re: The average (arithmetic mean) of the five numbers x, 91, 120, 134, and
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30 Jul 2018, 01:43



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The average (arithmetic mean) of the five numbers x, 91, 120, 134, and
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30 Jul 2018, 21:45
bettatantalo wrote: The average (arithmetic mean) of the five numbers x, 91, 120, 134, and 220 is what percent of the sum of the five numbers?
(A) 20% (B) 22% (C) 25% (D) 30% (E) It cannot be determined from the information given. You can either think logically and immediately choose the choice A or do algebraically and see the same result. In both cases, the logic plays a monumental role in this problem. Finding Average: \(\frac{x+565}{5}\)
[b]The Sum x+565 The Sum is the total and the average is the part, so you can create an equation: \(\frac{x+565}{5}\) / x+565 = \(\frac{y%}{100%}\) You can see that we have two variables x and y, but have only one equation. So, algebraically it's somehow impossible to find x and y. But you also can notice that you divide the numerator of the first fraction into 5, which in percent form is 100/5 yields 20%.
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The average (arithmetic mean) of the five numbers x, 91, 120, 134, and
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30 Jul 2018, 22:55
Solution Given:• We are given 5 numbers: x, 91, 120, 134, and 220 To find:• Arithmetic mean of : x, 91, 120, 134, and 220 is what percent of the sum of the five numbers
Approach and Working: \(Average= \frac{Sum\ of\ the\ five\ numbers}{5}\) Method:1Hence, Average if \(\frac{1}{5}\) of sum of the five numbers. Thus, average is 20% of sum of the five number. Method:2• To convert average to percentage, we can multiply by 100. • Average= Sum of the five numbers/5 *100%= Average= 20% of Sum of the five numbers Hence, the correct answer is option A. Answer: A
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Re: The average (arithmetic mean) of the five numbers x, 91, 120, 134, and
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12 Sep 2018, 07:13
bettatantalo wrote: The average (arithmetic mean) of the five numbers x, 91, 120, 134, and 220 is what percent of the sum of the five numbers?
(A) 20% (B) 22% (C) 25% (D) 30% (E) It cannot be determined from the information given. OA: A\(Average = \frac{Sum\quad of \quad Elements}{Number \quad of \quad Elements}\) \(\frac{Average}{Sum\quad of \quad Elements} =\frac{1}{Number \quad of \quad Elements}\) Multiplying by 100 on both sides, we get\(\frac{Average}{Sum\quad of \quad Elements}*100 =\frac{1}{Number \quad of \quad Elements} * 100\) \(Number \quad of \quad Elements=5\) \(\frac{Average}{Sum\quad of \quad Elements}*100 =\frac{1}{5}*100=20\)



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Re: The average (arithmetic mean) of the five numbers x, 91, 120, 134, and
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14 Sep 2018, 08:00
bettatantalo wrote: The average (arithmetic mean) of the five numbers x, 91, 120, 134, and 220 is what percent of the sum of the five numbers?
(A) 20% (B) 22% (C) 25% (D) 30% (E) It cannot be determined from the information given. The average of x, 91, 120, 134, and 220 is: (x + 91 + 120 + 134 + 220)/5 The sum is: x + 91 + 120 + 134 + 220 So the average as a percent of the sum is: [(x + 91 + 120 + 134 + 220)/5]/(x + 91 + 120 + 134 + 220) = 1/5 = 20% Alternate solution: Since sum = average x quantity, the average is 1/quantity x 100 percent of the sum. Since here we have 5 numbers, the average is 1/5 x 100 = 20 percent of the sum. Answer: A
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