The scatter plot below shows the relationship between the length (x), in meters, and mass f(x), in kg, of a marine animal:

ordered pairs 1, 1 and 2, 11 and 3, 21 and 4, 31 and 5, 41 and 6, 52 and 7, 65 and 8, 71 and 9, 82 and 10, 94

Which of the following functions is best represented by the scatter plot?

Question

The scatter plot below shows the relationship between the length (x), in meters, and mass f(x), in kg, of a marine animal:

ordered pairs 1, 1 and 2, 11 and 3, 21 and 4, 31 and 5, 41 and 6, 52 and 7, 65 and 8, 71 and 9, 82 and 10, 94

Which of the following functions is best represented by the scatter plot?

amistre64 · Answer

and our functions are?  if you can post a screenshot it may prove useful

amistre64 · Answer

also, define for us what is meant by "best".

anonymous · Answer

attachment

anonymous · Answer

f(x) = 9 − 10.3x
 f(x) = −10.3 + 9x
 f(x) = −9 + 10.3x
 f(x) = 10.3 − 9x

amistre64 · Answer

ok, is the slope going to be positive or negative?

anonymous · Answer

positive

amistre64 · Answer

then we can rule out 2 options at the start

anonymous · Answer

wait no the first & last one

amistre64 · Answer

we want to keep b and c

amistre64 · Answer

so, how do we define a reasonable slope?  any ideas?

amistre64 · Answer

consider that we move from 1 to 10, i change of 9

we have 2 slopes to work with in our options

y/9 = 9

and 

y/9 = 10.3

it seem to me that y goes from 0 to about 95, which one gives us a y value closest to this?

anonymous · Answer

y/9=10.3 ?

amistre64 · Answer

i agree

amistre64 · Answer

a slope of 9 gets us to 81, too short,  so the 10.3 has to be better

amistre64 · Answer

another sort of test, let x = 10

-10.3 + 9(10) < 90

-9 + 10.3(10) > 90

anonymous · Answer

-10.3 + 9(10) < 90

anonymous · Answer

?

amistre64 · Answer

what is 90 - 10 ?

amistre64 · Answer

notice our point at x=10 is about 95,  or greater than 90

anonymous · Answer

f(x) = −10.3 + 9x ?

amistre64 · Answer

if thats your pick for an answer, im going to disagree.

amistre64 · Answer

we want about 95 when x=10

what is -10.3 + 9(10) ?

anonymous · Answer

its -10.3+9x

amistre64 · Answer

you havent answered my question

amistre64 · Answer

or, are you saying that is what some answer key gives you?  you arent being very clear to me.

anonymous · Answer

im saying that one of the answer choices i thought it was .... sorry

amistre64 · Answer

thats what i had thought you meant but wasnt sure.

-10.3 + 9(10) = 79.7

|dw:1432953041331:dw|

amistre64 · Answer

do you see that we are not very close to where we need to be?

anonymous · Answer

yea

amistre64 · Answer

-9 + 10.3(10) = 103-9 = 94

amistre64 · Answer

so out of the 2 options

f(x) = -9 + 10.3x  seems to work better for us

anonymous · Answer

yea it does

amistre64 · Answer

good luck :)