Aproject is graded on a scale of 1 to 5. if the random variable, x, is the project grade, what is the mean of the probability distribution below?

probability distribution

.45 |
.4 | ~
.35 | ~
.3 | ~
.25 | ~
.2 | ~ ~ ~
.15 | ~ ~ ~
.1 | ~ ~ ~ ~ ~
.05 | ~ ~ ~ ~ ~
0 |__
1 2 3 4 5
x
answer choices: a. 0.2 b. 0.4 c. 1 d. 3

The correct answer is D) 3.

The mean is 3

3

Step-by-step explanation:

Given that A project is graded on a scale of 1 to 5.

If the random variable, X, is the project grade, we have to find  the mean of the probability distribution below

Since X takes values as 1,2,3,4,5

from the picture given we find the frequency distribution of X

X    1    2     3     4    5     Total

f     2    4     8     4    2       20

fx    2    8    24   16  10      60

Mean =60/20 =3

Hence answer is 3

option 3 . (5x + 1) - (-10x + 6)

step-by-step explanation:

option 1 :

(4x + 3) + (-9x + 4)

or 4x+3 -9x + 4

or -5x + 7

option 2

(x - 2) - (6x - 9)

or x-2-6x + 9

or -5x + 7

option 3

(5x+ + 6)

or 5x + 1 + 10x -6

or 15x -5

option 4

-4x+2x+7-3x

-7x + 2x + 7

-5x + 7

hence only option 3 did   not satisfy the given simplify expression.

sadsdda

step-by-step explanation: