I’m guessing that x is the angle on the right that isn’t shown?
Anyways if that’s the case then:
We know that the sum of all the angles of a triangle add up to 180 degrees.
In this triangle we know that one angle is 55 degrees and the other is 90 degrees, so to find the last angle we do the sum of all the angles and we remove the 2 angles:
180- (55+90)= 35 degrees.
x= 35 degrees
Solution: We are given:

Using the empirical rule, we have:
covers 68% of data.
Also the percentage of values below mean = Percentage of values above mean = 50%
Now, let's find the z score for x=20

Therefore, the percentage of values greater than 1 standard deviation above mean 
Expected number of students = 16% of 100 = 16
Hey there!
We have 10 pieces of paper. The probability of drawing a 10 is 1/10. Therefore, if we were to draw ten times, the ten should probably be drawn once. If we multiplied our number of drawings by four (10*4=40), our outcome of seeing our slip with the ten should also quadruple and become four times. (1*4=4)
I hope that this helps! Have an awesome day!