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The average age of 4 boys is 12 years. If another boy of 14 years joins them, what's the average age of the whole group?

Community Answer

With four boys averaging 12 years old, the combined ages of the four boys would be 4 x 12 = 48. Add the age of the new boy to that total to get 48 + 14 = 62. Now divide this number by your total number of people (5) to find the average age: 62 / 5 = 12.4.

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The average age of 30 students of a class is 15 years. Average age remains unaltered even if 3 new students are admitted. The total age of 3 new students is what?

Donagan

Top Answerer

If the new students don't change the average age of the class, that means their average age is 15, too, which means their total age is 3 x 15 = 45 years.

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How do I compute the mode of these ages: 25, 26, 28, 30, 54, 54, 52?

Donagan

Top Answerer

Look at the given numbers, and decide which number appears most often in the list. That number is the mode.

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The average age of 39 students in a class is 13. When the teacher is also included in the group, the average is increased by 1. What is the age of the teacher?

Donagan

Top Answerer

The teacher's age is 53. If the 39 students' average age is 13, that means they have a total of 507 years between them (39 x 13 = 507). Let t = the teacher's age. Then (507 + t) is the total years of the students and the teacher. The average age of these 40 people would be (507 + t) / 40, which we're told is equal to 13 + 1, or 14. So (507 + t) / 40 = 14. Multiply both sides of the equation by 40: ( 507 + t) = 560. So t = 53.

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The average of 6 numbers is 4. If the average of two of those numbers is 2, what is the average of the other four numbers?

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Top Answerer

The sum of the six numbers is 24 (6 x 4). The sum of the two numbers is 4. Subtracting the second sum from the first sum gives you a third sum, the sum of the other four numbers. The third sum is 20. Dividing 20 by 4 gives you 5, the average of the other four numbers.

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Do I round age in research studies? Is 19.68 rounded to 20?

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It's not mandatory, but it's a common tactic to round ages. Yes, if you're rounding to the nearest whole number, 19.68 would be rounded to 20.

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The mean age of the combined group of men and women is thirty years. If the mean age of group of men is thirty two and that of the group of women is twenty five, what is the ratio of men to women?

Donagan

Top Answerer

There's a mathematical way of solving this, but there's also an easier way of looking at it: the group's average age is two years different from the men's average age, but it's five years different from the women's average age. That means that the men have 2½ times more influence on the group average than the women do. So the ratio of men to women is 2½ : 1, or 5 : 2.

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How do I calculate the mean of percentage data?

Donagan

Top Answerer

Treat percentages as you would any other data. Add the percentages, and divide by the number of percentages.

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The total weight of 6 rugby players is 540 kg, and the mean weight of 14 ballet dancers is 40 kg. How do I find the mean weight of the group of 20 rugby players and ballet dancers?

Donagan

Top Answerer

Total rugby weight: 540. Total ballet weight: 14 x 40 = 560. Total weight: 540 + 560 = 1,100. Total people: 20. Mean weight = 1,100 / 20 = 55 kg.

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At Lopez College, the number of professors that are male is 100 persons, and 200 persons are female. If the average age of males is 35 and the average age of the females is 27, what is the average?

Donagan

Top Answerer

[(100)(35) + (200)(27)] ÷ (100 + 200) = [(3500) + (5400)] ÷ (300) = 8900 / 300 = 29.67 years.

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A fifth grade elementary school class consists of two schoolteachers, 4 boys and 6 girls. The average age of teachers is 34, boys is 10 and girls is 11. What is the average age of the class?

Donagan

Top Answerer

[(2)(34) + (4)(10) + (6)(11)] ÷ (2 + 4 + 6) = (68 + 40 + 66) ÷ 12 = 174 ÷ 12 = 14½ years.

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Question

How do I find the mean age of something?

Donagan

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Mean age and average age are the same thing. Use the technique shown above.

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