Answer:
Step-by-step explanation:
You have the right numbers, but the wrong accounts.
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Let x represent the amount invested at 8% (the highest rate). Then the total interest is ...
.08x +.03(3000 -x) = .04(3000)
.05x = .01(3000) . . . . subtract .03(3000)
x = 3000/5 = 600
Matthew invested $600 at 8%, $2400 at 3%.
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<em>Comment on checking your answer</em>
You may notice that the overall interest rate is 4%, closer to 3% than to 8%. That means more of the money must be invested at 3% than at 8%.
Answer:
7/20 = x/400
Step-by-step explanation:
Answer:
z=-1.591
Step-by-step explanation:
Null Hypotheses,

So we use z-test for one population proportion (right-tailed test)
According to this informaton, we defined that

(critical value)
So our Rejection region is 

Not rejection.
Answer:
$17.50
Step-by-step explanation:
THATS THE TOTAL THE SALES TAX WOULD BE $0.75
thank you for your time
Answer:
58p+15
Step-by-step explanation:
First, we want to get rid of the parentheses in the equation. To do that, let's start with 7(1+10p). We multiply 7 by each item in the parenthesis, and get 7+70p. Keep that little thing in mind, we will use it later. Next, same process with the other part, and we get 8+48p. We multiplied both parts out, so now we just add like terms. 7 and 8 don't have letters, so we add them to get 15. 10p and 48p do have letters, so we add those together and get 58p. We can't add that to the other numbers, because 58p is 58 times p, and 15 doesn't have that p so it wouldn't work without knowing p. What we are left with, by simplifying the problem, is 58p+15, or 15+58p. The order doesn't matter, as long as you have that answer.