ShmoopTube

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Thank you We sneak and here's your shmoop du jour

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brought to you by chlorophyll Try telling these guys it's

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Not easy being green Check out this diagram and passage

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right with diagrams Relation All right Which of the following

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most nearly represents the line of best fit All right

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here the potential answer will you Okay we're usually more

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concerned with which pair of pants represents the line a

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best fit but well anything we can wear without having

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a suck in our guts it's high marks from us

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but okay so we've got this graph here and there's

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a red line going across it That's the line of

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best fit if ever there was one Our mission we

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choose to accept it is to figure out which one

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of these four line equations represents that line All right

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if we're interested in any of them representing us while

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we get their business card afterwards okay so the first

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thing we should notice is that this line moves downward

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from left to right indicating a negative slope Unfortunately for

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us it doesn't help us rule out any of the

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answer choices since all four of them have a negative

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sign in front of the ex term right there meaning

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they're all equations for lines with negative slopes Well great

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guess we're gonna have to do this the hard way

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We're told two of the points that fall along the

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line at one point five and sixteen point too and

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then more fifteen point seven six oh goody decimals should

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be fun Fortunately however as long as we have two

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points on a line we can find it slope Well

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we'll take our old reliable slope formula Why To minus

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y wan over Acts to minus x 1 and plug

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in r point coordinates Your slope is going to be

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fifteen point seven six minus sixteen point two over four

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minus one point five that'll simmer down a negative point

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for for over two point five we'll do the division

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dance and we wind up with a slope of negative

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point one seven six but looks like we can narrow

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it down to options See andy well a and b

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you're going overboard without a life preserver Best of luck

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to you both All right We've checked a slope off

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our to do list but we still need the y

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intercept will to find it We can use the slow

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formula again this time setting x two equal to zero

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will also need one of our points that we know

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are on the line and we'll go with four fifteen

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point seven six since at least there's one whole number

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in there to make our lives A bit easier All

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right now we've got the points for fifteen point seven

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six zero why too And we could do the same

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thing we did earlier to find that why value Remember

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we're setting this whole thing equal to a slope of

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negative point one seven six So negative point one seven

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six equals y two minus fifteen point seven six over

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zero minus four Just negative for we can now multiply

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both sides by negative for to get positive Point seven

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oh for equals y two minus fifteen point seven six

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and finally add fifteen point seven six to both sides

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and why two comes out to be sixteen point four

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six four Well we only have two round that off

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and we've got a perfect match for option d Why

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equals negative point One seven six x plus sixteen point

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four six not a bad exercise Speaking of which we

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could use some exercise we'd love to fit that pair

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of skinny jeans we wore back in high school No

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