Answer:
Option B) 9.1
Step-by-step explanation:
We are given the following in the question:
Average score = 490.4
Standard deviation = 63.7
Sample size, n = 49
Formula:

Putting values, we get,
Standard error =

Thus, the correct answer is
Option B) 9.1
We know this angle is a 90° or a right angle. So another words we know adding these 2 expressions equals to 90°.
(4x + 3) + (x - 8) = 90°
Remove the parentheses and combine the like-terms:
5x - 5 = 90°
Add 5 on both sides:
5x = 95°
Divide 5 on both sides
x = 19
You answer is x = 19.
The error Vincent made was that he only multiplied the left side of the inequality with 6 although he had to multiply on both sides
Step-by-step explanation:
Given inequality that the teacher wrote is:

Solving an inequality means that the variable should be isolated on left side of the inequality.
So multiplying both sides by 6

Vincent got the answer is x<-2 = > The error Vincent made was that he only multiplied the left side of the inequality with 6 although he had to multiply on both sides
Keywords: Inequality, solution
Learn more about inequalities at:
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The greatest common factor is 8
The percentage change in perimeter is 100%.
The percentage change in area is 300%
<h3>How to find perimeter and area?</h3>
The perimeter of the sandbox = 2l + 2w
where
Therefore,
perimeter = 2(10) + 2(6)
perimeter = 20 + 12 = 32 ft
The area of the sand box = lw
area = 10 × 6 = 60 ft²
If the length and width are doubled,
length = 2(10) = 20 ft
width = 2(6) = 12 ft
hence,
perimeter = 2(20) + 2(12) = 40 + 24 = 64 ft
area = 12 × 20 = 240 ft²
Therefore,
percentage change in perimeter = 64 - 32 / 32 × 100 = 100%
percentage change in area = 240 - 60 / 60 × 100 = 18000 / 60 = 300%
learn more on perimeter and area here: brainly.com/question/15322533
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