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:
The answer is in the step by step below (image)
Step-by-step explanation:
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Answer:
Alyssa had scored 3 goals today.
Step-by-step explanation:
Given:
Number of goals scored yesterday = 
Total number of goals scored in 2 games = 4
We need to find the number of goals scored today.
Solution:
Now Given:
Today she scored 3 times as many goals than yesterday.
So we can say that;
Number of goals scored today = 
Now we know that;
Total number of goals scored in 2 games is the sum of Number of goals scored yesterday and Number of goals scored today.
framing in equation form we get;

Dividing both side by 4 we get;

Number of goals scored yesterday = 1
Number of goals scored today = 
Hence Alyssa had scored 3 goals today.
Answer:
3/4.
Step-by-step explanation:
I just know. I studied constant of proportionality for a loooong time! if its wrong tell me.