All posts by mathconfidence

Get the Math and Points Jan 2016 CC Alg I #25

Jan 2016 A1 25

Linear vs Exponential
Look at the pattern of t(x) which are the y values.
Every time x goes up by 2 (from -3 to -1, or -1 to 1, 1 to 3, or 3 to 5), t(x) goes down by 2.5.
This means that there is a constant rate of change or slope and that the function is linear.
These points can be plotted on graph paper to see if they will make a line which they do :)

Here is some more practice from the awesome site www.emathinstruction.com

https://emathinstruction.com/wp-content/uploads/2014/11/CCAlg1-U6L8-Linear-Versus-Exponential.pdf

 

Get the Stats and Get the Points CC Alg I Jan 2016 #24

Jan 2016 A1 24

Residuals show how far the data is from the line of best fit.
If a line is a good fit for the data, then the residuals will be about half below and half above the x axis.  The residuals will also be close to the x-axis which means that their values are fairly small.
If the residual plot shows a pattern (see below), then a linear will not be a good fit.  See the link from Math Bits below:
http://mathbitsnotebook.com/Algebra1/StatisticsReg/ST2Residuals.html
Looking at the 4 choices, which looks most like the the left most graph that says “Random, No Pattern.  Linear Appropriate”?