Answer:
74.72
Step-by-step explanation:
Given
mean
Standard deviation 
For Top 25%
and Z value for 75 % is 0.6744
Thus score which separates the Top 25% of students is
6 ≤ 5(x - 4) -2(-x + 1)
First, distribute 5 to all terms within the first parenthesis, and -2 to all terms in the second parenthesis
6 ≤ (5x - 20 + 2x -2)
Combine like terms
6 ≤ (5x + 2x - 20 - 2)
6 ≤ 7x - 22
Isolate the x. Do the opposite of PEMDAS. Note that what you do to one side you to the other.
Add 22 to both sides
6 (+22) ≤ 7x - 22 (+22)
28 ≤ 7x
Divide 7 from both sides
28/7 ≤ 7x/7
28/7 ≤ x
4 ≤ x is your answer
Use a closed dot (because of the equal underneath) on 4, and go left with an arrow
hope this helps
Theoretical probability is the number of desired outcomes (heads) divided by the total number of outcomes (heads or tails). The actual outcome does not affect the theoretical probability. Mark is correct.
This is known as "5 take 3", where ordering is not important.
