Answer:
option A
Step-by-step explanation:
given,
10% A grades 80% B grades 10% C grades
This year, managers with scores less than 35 received C's and those with scores above 425 received A's.
The mean has to be middle of two corresponding cutoff value

μ = 230
Cutoff Off C grade corresponds with the area of 0.10 is table A.
corresponding z- score according to Table A
Z = -1.28
now, standard deviation



σ = 152.3
Correct answer is option A
Answer:

33 gallons of water to begin with.
Step-by-step explanation:
So we essentially are given two coordinates: (6,87) and (21,222). To find an equation, we simply need to find the slope and y-intercept. We know it's a linear equation because it's a steady stream, meaning a constant slope.
The slope is:

So, the rate at which the stream flows is 9 gallons per minute.
Now, let's find the initial amount of water. To do this, we can use point-slope form. Pick either of the two points. I'm going to use (6,87).

So, there were 33 gallons of water in the tank to begin with.
Option c : 9 is the answer.
Explanation:
The expression is 
We need to determine the subtracted value of the expression.
From the expression we can see that the expression contains two negative signs.
To simplify the expression, we know that, When we multiply two negative numbers then the product is always positive.
This means 
Thus, the expression can be written as

Adding the two numbers, we get,

Thus, the value of the expression is 9.
Hence, Option c is the correct answer.