Answer:
a. P(x>20)=0.19
b. P(x≥6)=0.72
c. P(x≤20)=0.81
d. A and C
Step-by-step explanation:
We know that:
1) the probability that a student makes fewer than 6 mistakes is 0.28

2) The probaiblity that a student makes between 6 to 20 mistakes is 0.53.

We will express the proabilibities in function of the information we have.
a. Probability that a student makes more than 20 mistakes.

b. Probability that the student make 6 or more mistakes

c. Probability that a student makes 20 mistakes at most

d. A and C, because A takes a event of more than 20 mistakes and C takes the event of 20 or less mistakes. Both events cover a probability of 1.
I believe the answer would be x = - 7/4
The number X is placed somewhere between 9 and 10. That's because 9 squared is 81 and 10 squared is 100.
Answer: 529 students
Step-by-step explanation:
To solve this, we will be using the formula for finding averages:
> (total sum of student weights) ÷ (total sum of students) = (average of student weights)
Plugging in the values that are given in the problem, you get:
> 16,293.2 ÷ x = 30.8
Where x is equal to the total sum of students. From here, it's a simple equation to isolate x, and find out what numerical value x is equal to. In case you are unsure how to do this, I've created a clear step by step process for how to do this (NOTE: The slash represents division, while the asterisk represents multiplication.):
> 16,293.2 / x = 30.8
> (16,293.2 / x) * x = (30.8) * x
> 16,293.2 = 30.8 * x
> (16,293.2) / 30.8 = (30.8 * x) / 30.8
> 529 = x
In total, there are 529 students in the school.