If you have answer choices that would be helpful.
If not I would assume that it means that giving every student the same test is an example of a controlled variable.
Answer:

And the value for n rounded up would be n = 174
Step-by-step explanation:
We have the following info given:
previous estimation for the deviation
the margin of error desired
represent the confidence
The Margin of error is given by:

If we solve for the value of n we got:

For this problem we know that the confidence is 98% so then the significance level would be
and the critical value would be:

And replacing we got:

And the value for n rounded up would be n = 174
Answer:
1 cup for every 16 tablespoons or 1:16
Answer:
x=-1
Step-by-step explanation:
3x+12-8x=19+2x (combine liked terms)
-5x+12+19=2x (move variable to the left-hand side and change its sign)
-5x-2x+12=19 (combine liked terms)
-7x=19-12 (divide both sides of the equation by -7)
x=-1
Answer:
a and d, and 123, 12 and 3