Answer:
a) Percentage of students scored below 300 is 1.79%.
b) Score puts someone in the 90th percentile is 638.
Step-by-step explanation:
Given : Suppose a student's score on a standardize test to be a continuous random variable whose distribution follows the Normal curve.
(a) If the average test score is 510 with a standard deviation of 100 points.
To find : What percentage of students scored below 300 ?
Solution :
Mean
,
Standard deviation 
Sample mean 
Percentage of students scored below 300 is given by,






Percentage of students scored below 300 is 1.79%.
(b) What score puts someone in the 90th percentile?
90th percentile is such that,

Now, 






Score puts someone in the 90th percentile is 638.
Answer————————-triangle 3
Hope this helps!!
Answer: C
Step-by-step explanation: thats just what i think the answer is
The answer is the first choice!!
Bear with my working out lol,
8x3 = 24in^2
9x12 = 108in^2
6x7 = 42in^2
(11x4) / 2 = 22in^2
Total = 196in^2
Try that, I couldn’t tell where the tip on the triangle fell at. So it could be wrong but that is what I got and what I would put :)