50%. students (in percent) who passed the second exam also passed the first exam.
Let's imagine that there are 100 kids in the teacher's class. We know that 40 of them passed BOTH tests, and 80 passed the second test.
Because if they weren't, they wouldn't have passed the first test and consequently wouldn't have passed both, we can be sure that the group of students who passed BOTH tests is only made up of the 80 who passed the second test.
Thus, both tests were passed by 40 of the 80 pupils who passed the second one:
40/80 = 1/2 = 50%.
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Answer:
Step-by-step explanation:

Answer:
A
Step-by-step explanation:
is the standard deviation of x.
The standard deviation is gotten by:
1. find the average of x-values (add up all the values and divide by number of numbers, which is 5)
2. subtract the average, x bar, from each of the values, square it, and add up the difference
3. Divide that final answer by n, which is 5
4. Take the square root of the answer
<em>Now, let's find the average (x bar):</em>
<em>x bar =
</em>
<em />
<em>Doing steps 2 & 3 together:</em>
<em>
</em>
<em />
<em>Doing step 4:</em>
<em>
</em>
<em />
Correct answer is A
<em />
<h3>
Answer: 920</h3>
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Explanation:
The front face is a triangle with area of base*height/2 = 15*8/2 = 60 square feet.
The back face is identical to the front face, so we have another 60 square feet.
The left rectangular wall is 20 ft by 8 ft tall. Its area is 20*8 = 160 ft^2
The right slanted rectangular face is 20 ft by 17 ft. Its area is 20*17 = 340 ft^2
Lastly, the bottom rectangle floor is 15 ft by 20 ft to give an area of 15*20 = 300 ft^2
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To summarize so far
- Front face = 60 ft^2
- Back face = 60 ft^2
- Left face = 160 ft^2
- Right slanted face = 340 ft^2
- Bottom floor = 300 ft^2
Add up those areas to get the overall surface area.
60+60+160+340+300 = 920
x=8
Step-by-step explanation:
move the +2 to the right side so it can be subtracted by the 5 to get 3. after that you square both sides of the equation to get rid of the square root symbol. then move the -7 to the right side and add it with 9. then you'll have 2x=16. then divide both sides by 2 to get x by its self and you are left with x =8