<span>If 3 is added to the number: x + 3
b) ...and the sum is tripled..
"The sum" is "x + 3" so: 3(x+3)
c) ...the result is 27 more than the number.
27 more than the number is x + 27
d) Put it all together:
3(x + 3) = x + 27
Solve for x:
1) Distribute the left side of the equation:
3x + 9 = x + 27
2) Subtract x from each side of the equation:
2x + 9 = 27
3) Subtract 9 from each side of the equation:
2x = 18
4) Solve for x:
x = 9
Check:
1) x = 9
2) 3(x + 3) = x + 27
3) 3 ([9] + 3) = [9] + 27
4) 3(12) = 9 + 27
5) 36 = 36
So, therefore The answer is correct</span>
Complete question:
A project 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?
Grade(X)_____ 1_____2_____3_____4_____5
Frequency____3 _____5____ 9 ____ 5 ____ 3
P(X) : _______ 0.1 ___0.2 ___0.4 ___ 0.2 __0.1
Answer:
3
Step-by-step explanation:
Given the probability distribution :
Grade(X)_____ 1_____2_____3_____4_____5
Frequency____3 _____5____ 9 ____ 5 ____ 3
P(X) : _______ 0.1 ___0.2 ___0.4 ___ 0.2 __0.1
The mean of the distribution :
Σ(X * P(X)) :
(1*0. 1) + (2 * 0.2) + (3 * 0.4) + (4 * 0.2) + (5 * 0.1)
0.1 + 0.4 + 1.2 + 0.8 + 0.5
= 3
That is the simplest form because 11 can't be divided
5× 6.25= 31.25 for 5 days
7×8.75= 61.25 for 7 days