Answer: A. We are 99% confident that the interval from 4.1 to 5.6 actually does contain the true value of mu.
Step-by-step explanation:
The correct interpretation of a 99% confidence interval is that we are 99% confident that the true population mean falls in it.
Given 99% confidence interval : 
Then, the correct interpretation : We are 99% confident that the interval from 4.1 to 5.6 actually does contain the true value of mu.
So all of the internal angles of a triangle will add up to 180 degrees. So if we add all of the expressions given and set them equal to 180, we can solve for x, then solve for each angle...
(2x + 1) + (3x - 3) + 9x = 180
2x + 3x + 9x + 1 - 3 = 180
14x - 2 = 180
14x = 182
x = 13
Now we can substitute 13 into each expression to find the value of each angle...
2x + 1 =
2(13) + 1 =
26 + 1 = 27 degrees
3x - 3 =
3(13) - 3 =
39 - 3 = 36 degrees
9x =
9(13) = 117 degrees
So the 3 angles are 27 degrees, 36 degrees, and 117 degrees.
The smallest is 27 degrees
** Note-- I don't see 27 degrees in the answer choices you gave, so I double checked my math (I didn't find any mistakes). Please check to see that the question is written correctly (pay close attention to plus and minus signs).
it depends how long the width and the length is. If the length is 5 cm and the width is 4 cm the perimeter will be 18cm. All you have to do is 5 doubled because there 2 sides for the length and 4 doubled because there are 2 sides for the width. I hope I have answered your question. XD