Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Pages: **1**

**Lan P****Member**- Registered: 2005-06-17
- Posts: 3

Hi all,

i need some help, Here the question:

1. What is the average (arithmetic mean) of 8, 7, 7, 5, 3, 2, and 2?

a. 3 4/7

b. 4 5/6

c. 4 6/7

d. 5

e. 6 4/5

I think the answer is A but the correct answer is C, i dont understand, please to explain for me.

2. If F (4) = 0 and f (6) = 6, which of the following could represent f (x)?

a. 2/3x - 4

b. x + 2

c. x - 4

d. 3/2x + 6

e. 3x - 12

The correct is E. I dont understand, please help

Offline

**im really bored****Member**- Registered: 2005-05-12
- Posts: 76

for the first part to find the mean just add all the numbers together like this:

8 + 7 + 7 + 5 + 3 + 2 + 2 = 34 then you divide that answer by the amount of terms or the amount of numbers, which is 7. so then it would look like this: 34/7 which simplifys down to 4 6/7.

For the second problem think of f(x) to be just another way to put down a variable, "y"

so f(x) would just be y. so then for f (4) = 0 means that some function gives out the value of 0 when y = 4 and the second part f (6) = 6 means that the same function gives out a 6 when y = 6. so then you know that the function has to give out a 0 when y = 4, so then you can just put in 4 for all the x's untill one of them gives out the value of 0, in this case it is 3x - 12 where

3*4 - 12, 12 - 12, 0 , so that equation works for the value of 4. then you check it with the other part where y = 6 so 3*6 - 12, 18 - 12, which turns out a 6. so the equations works for both the values so it is the right answer.

Offline

**Lan P****Member**- Registered: 2005-06-17
- Posts: 3

im really bored wrote:

for the first part to find the mean just add all the numbers together like this:

8 + 7 + 7 + 5 + 3 + 2 + 2 = 34 then you divide that answer by the amount of terms or the amount of numbers, which is 7. so then it would look like this: 34/7 which simplifys down to 4 6/7.

i dont understand: your mean 46/7 or 4*6/7 but 4*6= 24 please explain again for me. Thanks

Offline

**im really bored****Member**- Registered: 2005-05-12
- Posts: 76

What I meant is 4 and 6\7 as a mixed fraction simplyfied from the improper fraction of 34\7 where the 34 is divided by 7, 4 equal times with 6\7 left over, so it 4 and 6\7

*Last edited by im really bored (2005-06-19 14:38:06)*

Offline

**Lan P****Member**- Registered: 2005-06-17
- Posts: 3

i see now. thank a lot

Offline

Pages: **1**