You need to understand that you're solving for the average, which you already know: 90. Since you know the values of the first three exams, and you know what your final value needs to be, just set up the problem like you would any time you're averaging something.
Solving for the average is simple:
Add up all of the exam scores and divide that number by the number of exams you took.
(87 + 88 + 92) / 3 = your average if you didn't count that fourth exam.
Since you know you have that fourth exam, just substitute it into the total value as an unknown, X:
(87 + 88 + 92 + X) / 4 = 90
Now you need to solve for X, the unknown:
87
+
88
+
92
+
X
4
(4) = 90 (4)
Multiplying for four on each side cancels out the fraction.
So now you have:
87 + 88 + 92 + X = 360
This can be simplified as:
267 + X = 360
Negating the 267 on each side will isolate the X value, and give you your final answer:
X = 93
Now that you have an answer, ask yourself, "does it make sense?"
I say that it does, because there were two tests that were below average, and one that was just slightly above average. So, it makes sense that you'd want to have a higher-ish test score on the fourth exam.
Answer:
y=1/3 + 3
Step-by-step explanation:
y= 1/3x + b
(1) = 1/3(-6) + b
1 = -2 +b
3 = b
y=1/3 + b
Answer:
26
Step-by-step explanation:
[(7+3)5-4]/2+3
-To solve this equation you have to use PEMDAS
P- Parentheses
E- Exponents
M- Multiplication
D- Division
A- Addition
S- Subtraction-
- With MD and AS you work left to right of the equation since they are in the same spot. (PE[MD][AS])
Step 1) [(10)5-4]/2+3
- First you do "P," parentheses, so you add 7+3=10
Step 2) [50-4]/2+3
- Next you do "M," multiplication, and multiply 10x5=50
Step 3) [46]/2+3
- Then you do "S," subtraction, and subtract 50-4=46
(FYI: Steps 1-3 were still in the parentheses. We had to start with the parentheses in the parentheses, work PEMDAS, and now we are out of the parentheses and have to work PEMDAS on the rest of the problem.)
Step 4) 23+3
- Now we do "D," division, and divide 46/2=23
Step 5) 23+3=6
- Finally we do "A," addition, and add 23+3=26 so the answer is 26
(FYI: "/" means division)
Y : x
14 : 18
31 : x
18*31/14=x
39.85714286
ANSWER
x=39.86
Answer:
what’s the inequality? I only see the value of 20
Explanation: