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
I guess it’s A not sure tho
Answer:
1 Pen cost $2.25
Step-by-step explanation:
Assume:
Cost of Pen = a
Cost of pencil = b
Cost of notebook = c
a = 3b -------------------(1)
c = 4a -------------------(2)
2a + 6b + c = $18 -----(3)
From equation (1), b = a ÷ 3 ---------(4)
Substitute equations (2) and (4) in equation (3)
2a + 6 * (a ÷ 3) + 4a = $18
2a + 2a + 4a = $18
8a = $18
a = $2.25
Therefore, 1 Pen cost $2.25
Answer:
Mean- the average of data, meaning you add up all the numbers, and then divide the sum of the numbers by how many numbers there are. For example:
2, 2, 3, 4, 6, 6, 9.
7 numbers total.
2 + 2 + 3 + 4 + 6 + 6 + 9 = 32
32 ÷ 7 = 4.57
The mean would be 4.57.
Median- the middle point of the numbers. You cross off each of the numbers until you have one last number standing. If you have an even number of numbers, you find the middle of the last two numbers you crossed off. For example:
2, 2, 3, 4, 6, 6, 9
2, 3, 4, 6, 6
3, 4, 6
4
4 would be the median.
Mode- the largest number on the data.
Range- subtract the mode (largest number) from the smallest number to get range. For example:
2, 2, 3, 4, 6, 6, 9
9 - 2 = 7
7 would be the range.
Step-by-step explanation: