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.
Collect like terms (x + 7x) + (-1 + 4 - 3)
Simplify
Answer: 8x
The correct answer is -3 through -6.
Answer:
the largest angle is opposite the largest side and the shortest angle is opposite the shortest side
Step-by-step explanation:
The required value of y is 2645 / 77 when x = 77.
Step-by-step explanation:
1. Let's check the information given to answer:
if y varies inversely as x, and y = 23 when x = 115. Find y when x=77
2. What is y when x = 77?
As the statement "y varies inversely as x" translates into y = k/x
If we let y = 23 and x = 115, the constant of variation becomes
23 = k ÷ 115
k = 23 × 115
k = 2645
Thus the specification equation is y = 2645 ÷ x . Now, letting x = 77, we obtain
y = 2645 ÷ x
y = 2645 ÷ 77
<u>So, The required value of y = 2645 / 77 when x = 77</u>
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<u>#learnwithBrainly</u>
