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3 years ago

11

Rue or false? using the regression equation to make predictions for values of the predictor variable outside the range of the ob

served values of the predictor variable is risky and unreliable.

1 answer:

Alexxx [7]3 years ago

5 0

True,.................

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Find the least squares regression equation using the school year (in number of years after 2000) for the input variable and the

Ad libitum [116K]

<u>Answer-</u>

<em>The least squares regression equation using the school year (in number of years after 2000) for the input variable and the average cost (in thousands of dollars) for the output variable is "y=0.937x+12.765" .</em>

<u>Solution-</u>

The independent variable / input variable= x = Number of years after 2000 ( = year-2000)

The dependent variable / output variable = y = Average cost in thousands of dollars

(The table has been attached herewith.)

To find the regression equation for a group of (x,y) points,

We have to calculate the slope and y-intercept, then we can put those values in the equation y = mx + c ( Slope - Intercept formula)

We know that,

$Slope=m=\frac{N\sum xy -\sum x\sum y}{N\sum x^{2}- (\sum x)^{2}}$

Putting the values from the table,

$m=\frac{(8 \times 1020.206)-(52 \times 150.894)}{(8 \times 3810)-(52^2)}$

( ∵ Instead of 150,894 we have to put 150.894 as we have find the line for year and thousands of dollars )

$\Rightarrow m =\frac{8161.648-7846.488}{3040-2704} =\frac{315.16}{336}=0.937$

Now, for the y-intercept,

$c =\frac{\sum y -m(\sum x)}{N}$

Putting the values,

$c=\frac{150.894-(52 \times 0.937)}{8}=\frac{102.125}{8}=12.765$

Now, putting the values of c and m, in the Slope-Intercept formula,

$y=0.937x+12.765$

3 0

4 years ago

What is the equation of a line that is parallel to y=47x−3 and passes through (14, 4)?

Shtirlitz [24]

Answer:

Step-by-step explanation:

The equation of a straight line can be represented in the slope-intercept form, y = mx + c

Where

m = slope

c = intercept

The equation of the given line is

y = 47x - 3

Comparing with the slope intercept equation, m = 47

If two lines are parallel, it means that they have equal slope. This means that the slope of the line passing through (14, 4) is 47

We would determine the intercept, c by substituting m= 47, x = 14 and y = 4 into y = mx + c. It becomes

4 = 47× 14 + c

4 = 658 + c

c = 4 - 658 = - 654

The equation becomes

y = 47x - 654

6 0

3 years ago

Lena paid $18.96 for 3pounds of coffee. What is the cost per pound for this coffee

STatiana [176]

Answer:

6.32

Step-by-step explanation:

divide 18.96 by 3 and the outcome is 6.32

6 0

3 years ago

You and three friends go to the town carnival. You have a coupon for $20 off that will save your group money! If the total bill

Lunna [17]

Answer:

30 that singular tickets for each friend and if your asking for total it would be 120. :)

Step-by-step explanation:

They paid 100 but they had a 20$ off coupon, this means the orignial total would be $120 so 120 divided by 4 (there's four people) = $30 each :)

hope this helped

5 0

3 years ago

Can you please help me answer this question what's a+3

Inessa [10]

Answer:

a+3

Step-by-step explanation:

You cannot go any further in answering this question. These two terms are not like terms so they cannot be combined. Therefore, the answer is just a+3 itself.

7 0

3 years ago