Answer: 0.16
Step-by-step explanation:
Given that the run times provided are normally distributed ;
Mean(x) of distribution = 3 hours 50 minutes
Standard deviation(s) = 30 minutes 
The probability that a randomly selected runner has a time less than or equal to 3 hours 20 minutes 
3 hours 20 minutes = (3 hrs 50 mins - 30 mins):
This is equivalent to :
 [mean(x) - 1 standard deviation]
z 1 standard deviation within the mean = 0.84
z, 1 standard deviation outside the mean equals:
P(1 - z value , 1standard deviation within the mean)
1 - 0.8413 = 0.1587
= 0.16
 
        
             
        
        
        
Answer: 6/5
Step-by-step explanation:
 
        
             
        
        
        
1. I feel the need to explain things first before I write the numeric value. 
   Let x be the total number of students in the school. 25% of this value is given to be 35.
                        (0.25)x = 35
The value of x is 140. 75% of this value is the answer which is equal to 105.
2. Let y be the alternative schools. With this, the number of charter schools is 2x - 6 which is equal to 52 
                              2x - 6 = 52
The value of x is 29. Therefore, there are 29 charter schools. 
        
             
        
        
        
Answer:
-3
Step-by-step explanation:
Simplifying
4(4m + -3) + -1(m + -5) = -52
Reorder the terms:
4(-3 + 4m) + -1(m + -5) = -52
(-3 * 4 + 4m * 4) + -1(m + -5) = -52
(-12 + 16m) + -1(m + -5) = -52
Reorder the terms:
-12 + 16m + -1(-5 + m) = -52
-12 + 16m + (-5 * -1 + m * -1) = -52
-12 + 16m + (5 + -1m) = -52
Reorder the terms:
-12 + 5 + 16m + -1m = -52
Combine like terms: -12 + 5 = -7
-7 + 16m + -1m = -52
Combine like terms: 16m + -1m = 15m
-7 + 15m = -52
Solving
-7 + 15m = -52
Solving for variable 'm'.
Move all terms containing m to the left, all other terms to the right.
Add '7' to each side of the equation.
-7 + 7 + 15m = -52 + 7
Combine like terms: -7 + 7 = 0
0 + 15m = -52 + 7
15m = -52 + 7
Combine like terms: -52 + 7 = -45
15m = -45
Divide each side by '15'.
m = -3
Simplifying
m = -3
Hope this helped :)
 
        
             
        
        
        
Answer:
The circumference of a circle is calculated by multiplying the diameter of a circle by π (π × d) . The formula to calculate the circumference of a circle is usually written c = πd .
Step-by-step explanation:
Pi is a number that is approximated by 3.14, or 22/7. It is the ratio of the circumference to the diameter of any circle. This ratio can be rearranged to find circumference of a circle by multiplying pi times diameter.
I hope this helps.