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0
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Which equation is the BEST fit for the data in the graph? LINK BELOW

https://postimg.org/image/k7wvdpqqv/64b29e17/
Question 3 options:

y = x + 3

y=9/8x+4

y=8/9x+4

y = x + 4
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Which line best fits the data in the scatter plot? LINK BELOW

https://postimg.org/image/mxy4kcyc5/885f56a1/
Question 7 options:

y = 2x - 1

y = 2x + 1

y = 2x + 2

y = 2x + 3
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The graph shows number of blooms a rose bush has if x units of fertilizer is added to the soil. If the trend continues, about how many rose blooms would the bush have if 12 units of fertilizer is added? LINK BELOW

https://postimg.org/image/ul97pj78z/1ab41b7b/

Question 6 options:

2

18

22

26
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The scatter plot shows the average monthly outside temperature and the monthly electricity cost.

Based on the scatter plot, what is the best prediction for the electricity cost if the temperature for the month is 21°C? LINK BELOW

https://postimg.org/image/oo7d07mw7/118d6f07/

Question 10 options:

\$450

\$500

\$600

\$700

Jun 2, 2017

#1
+1

3.

I think what they want is the line that passes through the most points. The easiest way to see which one passes through the most points is to look at a graph here: desmos

You can hide/show a line by clicking on the colored circles at the very left end of the window.

So, we can see that the blue line passes through the most points.

That is, the line   y = x + 3   .     (I don't like this answer very much though, to be honest!)

7.

This one is a little harder to see where exactly the points are. Let's just find the equation of a line that passes through the first point,  (1, 1)  , and last point,  (3, 5) .

slope = (5 - 1)/(3 - 1)   =   4/2   =  2

y - 1 = 2(x - 1)

y - 1 = 2x - 2

y = 2x - 1               Based on this, we can see the other options are way off!

6.

Hmmm, I don't really see much of a predictable trend here!  But, the amount of blooms will probably be greater than 18. So, my guess is 22.

10.

From     ≈ 12º   to  ≈ 17º    the cost changed from  ≈  \$200  to   ≈  \$400

That is, with a 5º change in temperature, the cost changes about \$200

So...from 16º to 21º   the cost will probably change from ≈  \$300  to   ≈  \$600

Jun 2, 2017
#2
+2

1.  I used this tool to generate the best-fit line :

http://www.alcula.com/calculators/statistics/linear-regression/

The generated equation  is   about   y =  1x  + 3.26   which is closest to

y  = x + 3    ........So....hectictar's answer is good

2.  This looks to be almost linear.....the best fit appars to be  y  = 2x -1......as hectictar said

3. This is the same graph as 2.....  so.....2(12) - 1  = 23.......

"22"  seems to be the closest value

4. Very difficult to tell what the exact values are, but hectictar's logic seems sound.....!!!!   Jun 2, 2017
edited by CPhill  Jun 2, 2017
#3
+1

On the last one I actually messed up!

\$300 + \$200 is \$500   , not  \$600  !

But...I could still see it being \$600 !

I can also see it being \$500    ... hectictar  Jun 3, 2017