the average rainfall for 5 days was 3inches per day. it rained 1 inch on the first day, 4.5 inches on the second day, 2.9 inches on the third day, and 4 inches on the fourth day. how many inches did it rain on the fifth day. please help! i will give medals!!

Question

anonymous · Answer

@iGreen

igreen · Answer

Make an equation.

$\sf \dfrac{1 + 4.5 + 2.9 + 4 + x}{5}=3$

igreen · Answer

Solve for 'x'.

The mean over 5 days is 3.

To find the mean, add up all the inches of rainfall and divide by how many days.

This gives us that equation.

igreen · Answer

First, multiply 5 to both sides, can you do that?

anonymous · Answer

when you say multiply 5 by both sides do you mean by all the average numbers?

anonymous · Answer

like 1, 4.5, 2.9, and 4

igreen · Answer

$\sf \dfrac{1 + 4.5 + 2.9 + 4 + x}{5} \cdot 5=3\cdot 5$

$\sf \dfrac{1 + 4.5 + 2.9 + 4 + x}{\cancel 5} \cdot \cancel{5}=3\cdot 5$

$\sf 1 + 4.5 + 2.9 + 4 + x = 3 \cdot 5$

Simplify the right side of the equation.

anonymous · Answer

my final answer before I posted the question was 2.6 inches so do you know what i did wrong?

igreen · Answer

2.6 is correct.

$\sf 1 + 4.5 + 2.9 + 4 + x = 15$

$\sf 12.4 + x = 15$

$\sf x = 2.6$

anonymous · Answer

oh ok sweet. I thought you were saying that 3.5 was the answer. thanks for the help!

igreen · Answer

No problem.