She has = 5- 2 = 3
3 >= y * 0.55 > 0.55
5 > y > 1 (truncate in case of count)
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
Answer:
1 = 137
2 = 43
3 = 43
4 = 137
Step-by-step explanation:
for the first line, do (180-137 = 43)
then, 43 would be corresponding angle to 2 - making them equal
2 would be vertically opposite to 3, making them equal
137 and 1 are corresponding- making them equal
4 is vertically opposite to 1 - making them equal