Help with Maths Question? (Analysing Data) (1 Viewer)

[apples-x3]

Help with Maths Question? (Analysing Data) --Solved, Thanks!

How would you solve a problem where it gives you no numbers?
E.g.
1. The average of five numbers is 7. A sixth number is added and the new average is 8. Find the sixth number.
2. The mean of a set of six scores is 20. What is the sum of these six scores?

I'd love for full working out so it'll help me understand better. Thanks

 

[SpiralFlex]

I feel like blue today.

1. Let us consider the sum of the numbers before we average them.

We have numbers. The average is . So the sum of the numbers must be

Similarly, for numbers. The average is . So the sum of the numbers must be

Now,



Hence the sixth number is


2. The same thing applies. Mean means average, so the average of six scores is

The sum is

 

[nightweaver066]

1. Average of 5 numbers is 7. So adding the 5 numbers together must total 35.
Adding a sixth number and having the new average as 8 means the total must now be 48.
That means the new number that has been added must be 13.

2. Mean = average. Remember that the average is the addition of all the terms together divided by the number of terms you have. Multiply 20 by 6 to get the sum of all 6 scores = 120.

 

[apples-x3]

Woah that was quick xD Thank you both of you for your answers! I understand now, thanks