Answer: c) About 16% of the variation in value of the car is explained by a linear relationship with the age of the car.
e) The correlation coefficient, r, is 0.397.
Step-by-step explanation:
Given that:
Coefficient of determination (r²) between two variables, age of car (x) and value of car (y) = 0.158
Correlation of determination (r²) of 0.158 = (0.158 × 100% = 15.8% of the variation between the two variables can be explained by the regression line). Hence, about 16% of the variation between age and value of car can be explained by the linear relationship.
Coefficient of correlation (r) = sqrt(r²) = sqrt(0.158) = 0.397
A constant is any number, anywhere on the number line.
A variable is an unknown, x y z n etc
One way to look at this is to make 2 equations and treat it as a set of equations. We will make the cost of a donut equal to x, and the cost of a coffee equal to y.
Harold's order:
4x + 2y = 4.08
Melinda's order:
2x + 3y = 3.92
To combine these equations, we need to cancel out either x or y:
4x + 2y = 4.08
<span>2x + 3y = 3.92
</span>
4x + 2y = 4.08
<span>4x + 6y = 7.84
</span>
4x + 2y = 4.08
<span>-4x - 6y = -7.84
</span>
We can now combine these equations:
4x + 2y = 4.08
<span>-4x - 6y = -7.84
</span>
-4y = -3.76
y = 0.94
Therefore the cost of a large coffee is $0.94. We can plug this into either original equation to find the cost of a donut.
<span>4x + 2y = 4.08
</span>4x + 2(0.94) = 4.08
4x + 1.88 = 4.08
4x = 2.20
x = 0.55
The cost of a donut is $0.55, and the cost of a large coffee is $0.94.
