What's an equivalent equation for -5(3-2x)
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Answer:
Step-by-step explanation:
Hello!
The given data corresponds to the variables
Y: Annual Maintenance Expense ($100s)
X: Weekly Usage (hours)
n= 10
∑X= 253; ∑X²= 7347; = ∑X/n= 253/10= 25.3 Hours
∑Y= 346.50; ∑Y²= 13010.75; = ∑Y/n= 346.50/10= 34.65 $100s
∑XY= 9668.5
a)
To estimate the slope and y-intercept you have to apply the following formulas:
^Y= a + bX
^Y= 10.53 + 0.95X
b)
H₀: β = 0
H₁: β ≠ 0
α:0.05
F= 47.62
p-value: 0.0001
To decide using the p-value you have to compare it against the level of significance:
If p-value ≤ α, reject the null hypothesis.
If p-value > α, do not reject the null hypothesis.
The decision is to reject the null hypothesis.
At a 5% significance level you can conclude that the average annual maintenance expense of the computer wheel alignment and balancing machine is modified when the weekly usage increases one hour.
b= 0.95 $100s/hours is the variation of the estimated average annual maintenance expense of the computer wheel alignment and balancing machine is modified when the weekly usage increases one hour.
a= 10.53 $ 100s is the value of the average annual maintenance expense of the computer wheel alignment and balancing machine when the weekly usage is zero.
c)
The value that determines the % of the variability of the dependent variable that is explained by the response variable is the coefficient of determination. You can calculate it manually using the formula:
This means that 86% of the variability of the annual maintenance expense of the computer wheel alignment and balancing machine is explained by the weekly usage under the estimated model ^Y= 10.53 + 0.95X
d)
Without usage, you'd expect the annual maintenance expense to be $1053
If used 100 hours weekly the expected maintenance expense will be 10.53+0.95*100= 105.53 $100s⇒ $10553
If used 1000 hours weekly the expected maintenance expense will be $96053
It is recommendable to purchase the contract only if the weekly usage of the computer is greater than 100 hours weekly.
ANSWER
Find out the how many 3, 4, and 5 point questions could there be.
To proof
Let us assume that the 3 points based question be = x
Let us assume that the 4 points based question be = y
Let us assume that the 5 points based question be = z
As given
An instructor wants to write a test with 25 questions
than the equation become in the form
x + y + z = 25
he quiz to be worth a total of 100 points.
than the equation is becomes
3x + 4y + 5z =100
As given
He wants the number of 3-point questions to be 4 less than the number of 4-point questions
x = y -4
Than the three equation are
x + y + z = 25 ,3x + 4y + 5z =100 and x = y -4
put x = y -4 in the x + y + z = 25 ,3x + 4y + 5z =100
than
2y + z = 29, 7y +5z= 112
multiply 2y + z = 29 by 5 and subtracted 7y +5z= 112
10 y -7y + 5y -5y = 145 -112
3y = 33
y =11
put in the x = y -4
x = 11-4
x= 7
put the value of x ,y in the x + y + z = 25
7 + 11 +z =25
18 +z = 25
z = 25 -18
z=7
therefore
numbers of the 3 point question be = 7
numbers of the 4 point question be = 11
numbers of the 5 point question be = 7
Hence proved