Homework help

[kelvinhall05]

Can someone help me with the last 2 questions on my homework? I'm supposed to find 5 numbers that (combined) have a mean of 100, and another 5 numbers with a mean of 75 and a range of 8. I know how to do range, mean, median, etc. but I need some help. Can you help me? Thanks!

[Mug]

first one, pick 5 numbers that add up to make 500. Any numbers.

I picked 101, 102, 103, 98, 96.

 

second one, pick 3 numbers between 71 and 79 that add up to 225.

I picked 73, 78 and 74. The numbers of this answer is therefore 71, 79, 73, 78, 74. Easy.

 

How? Well, rearrange the equation you use to get averages, times the mean by the number of numbers (5) and you'll get the sum of the numbers. From there, you can easily pick numbers. You could even pick ludicrous numbers as long as they all average out.

[Dash Lambda]

To find a mean, you find the sum of the items and divide it by the number of items. Therefore, for a given mean, the items need to add up to that mean times the number of items.

So, let's say I want to find 3 numbers whose mean is 10. Since I would divide the sum by 3 to get 10, I work backwards and find that in order to satisfy the mean, the numbers would have to add up to 30. At that point, I just choose any three numbers that add up to 30.

 

For the second question, you do the same thing except you just add the condition that the difference between the highest and lowest number is your range.

So, if I wanted 3 numbers with a mean of 10 and a range of 5, then I could choose as example 8, 13, and 9. The range is 13-8=5, and the mean is (8+9+13)/3=10.

[kelvinhall05]

10 hours ago, Mug said:

first one, pick 5 numbers that add up to make 500. Any numbers.

I picked 101, 102, 103, 98, 96.

 

second one, pick 3 numbers between 71 and 79 that add up to 225.

I picked 73, 78 and 74. The numbers of this answer is therefore 71, 79, 73, 78, 74. Easy.

 

How? Well, rearrange the equation you use to get averages, times the mean by the number of numbers (5) and you'll get the sum of the numbers. From there, you can easily pick numbers. You could even pick ludicrous numbers as long as they all average out.

 

 

10 hours ago, Dash Lambda said:

To find a mean, you find the sum of the items and divide it by the number of items. Therefore, for a given mean, the items need to add up to that mean times the number of items.

So, let's say I want to find 3 numbers whose mean is 10. Since I would divide the sum by 3 to get 10, I work backwards and find that in order to satisfy the mean, the numbers would have to add up to 30. At that point, I just choose any three numbers that add up to 30.

 

For the second question, you do the same thing except you just add the condition that the difference between the highest and lowest number is your range.

So, if I wanted 3 numbers with a mean of 10 and a range of 5, then I could choose as example 8, 13, and 9. The range is 13-8=5, and the mean is (8+9+13)/3=10.

 

I know how to calculate it, just not this specific problem.

Anyways, my dad came home and helped me, thanks anyways!