Answer:

So then the best answer for this case would be:
C. 2.78
Step-by-step explanation:
For this case we have the following probabability distribution function given:
Score P(X)
A= 4.0 0.2
B= 3.0 0.5
C= 2.0 0.2
D= 1.0 0.08
F= 0.0 0.02
______________
Total 1.00
The expected value of a random variable X is the n-th moment about zero of a probability density function f(x) if X is continuous, or the weighted average for a discrete probability distribution, if X is discrete.
If we use the definition of expected value given by:

And if we replace the values that we have we got:

So then the best answer for this case would be:
C. 2.78
Answer:
534
Step-by-step explanation:
multiply 13.45 by 40 and you will get 534
AND?!?
.....................................
Answer:
<em>( About ) 1.77 seconds; Option B</em>
Step-by-step explanation:
We are given the equation h ( t ) = - 16t^2 + 50, so in order to determine the time let us determine the x - intercept for y ⇒ 0;
- 16t^2 + 50 = 0,
- 16t^2 = - 50,
t^2 = 25 / 8,
Thus t ⇒ √ ( 25 / 8 ), and t ⇒ - √ ( 25 / 8 ),
t ⇒ ( 5√2 )/ 4, and - ( 5√2 )/ 4,
But time is represented only by a positive value, thus
t ⇒ ( 5√2 )/ 4 = 1.767766953......., ( About ) 1.77 seconds
<em>Answer; ( About ) 1.77 seconds; Option B</em>