Answer:
5.5
Step-by-step explanation:
The rate of change of a relationship is the ratio of corresponding changes in value. Symbolically, we indicate a change with the greek letter Δ (pronounced "delta"). A change in x is written Δx ("delta eks") and a change in y is written Δy ("delta why"). We're looking for the ratio Δy/Δx ("delta y over delta eks").
Mathematically, Δx and Δy are the differences between two corresponding x an y values. To pick these, we can take any two rows in our table. Let's pick rows 4 and 2, nice whole numbers:
[tex]\Delta{x}=20-10=10\\\Delta{y}=112-57=55\\\Delta{y}/\Delta{x}=55/10=11/2=5.5[/tex]
We can confirm that this holds for every other pair, too - picking rows 2 and 1 as an example:
[tex]\Delta{x}=10-5=5\\\Delta{y}=57-29.5=27.5\\\Delta{y}/\Delta{x}=27.5/5=275/50=11/2=5.5[/tex]
