Solve $f^{\text{'}\text{'}}(x)=0.$ Round to the nearest tenth of a year. What does this value$($s$)$ represent in the context?

Using the table and scatterplot, draw $6$ LEFT bound rectangles to create a Reimann Sum. Use it to approximate the total number of cell phones sold between $2010$ and $2020.$

$\backslash$table$[[$Rectangle$,$Height,Width,Area$],[1,,,],[2,,,],[3,,,],[4,,,],[5,,,],[6,,,]]$

Evaluate ${\displaystyle \underset{0}{\overset{10}{}}}(171700x^3-2276000x^2+8725000x+90120000)dx$ to approximate the total number of cell phones sold between $2010$ and $2020.$

Compare and contrast the two methods to estimate the total number of cell phones sold between $2010$ and $2020.$ Which do you believe would be more accurate of an approximation? Why?

JUST SOLVE NUMBER $8!!$ THANK YOU!!