Question

In 2007, people in a particular region spent an average of 15 minutes daily on their mobile devices. By 2014 that figure was up to 196 minutes daily. Assuming the increase in usage was constant, the number of minutes used can be calculated by the equation y = 25.9x + 15, where x represents the number of years after 2007 and y represents the number of daily minutes spent on mobile devices. Complete (a) through (E)(A) how many minutes daily did people in this region spend on their mobile devices in 2011? (B) in which year did an average mobile device user spend approximately 92.7 minutes on her or his mobile devices? Type a whole number (C) interpret the slope of the equation y= 25.9x+ 15 choose the correct interpretation of the slope below.A. Each year, people in this region spend 15 fewer daily minutes on their mobile devices B. Each year, people in this region spend 25.9 fewer daily hours on their mobile devices C. Each year, people in this region spend 15 additional daily hours on their mobile devices D. People in this region spent an average of 25.9 daily minutes on their mobile devices from 2007 to 2014 E. People in this region spent an average of 15 daily hours on their mobile devices from 2007 to 2014 F. Each year, people in this region spend 25.9 additional daily minutes on their mobile devices

Answer 1

Given:

The equation is,

$y=25.9x+15$

Here, y represents the number of daily minutes spent on mobile devices.

x represents the number of years after 2007 .

A) The number of minutes spent on mobile device in 2011 that means after 4 years from 2007.

$\begin{gathered} y=25.9x+15 \\ y=25.9(4)+15 \\ y=118.6 \end{gathered}$

Hence, the number of daily minutes spent on mobile in the year 2011 is 118.6.

B) To find the year in which user spend approximately 92.7 minutes is,

$\begin{gathered} y=25.9x+15 \\ 92.7=25.9x+15 \\ 77.7=25.9x \\ x=3 \end{gathered}$

x=3 means after 3 years from 2007 that is in the year 2010.

C) The slope of equation is,

$\begin{gathered} y=25.9x+15 \\ \text{compare it with slope intercept form y=mx+b} \\ \Rightarrow slope=m=25.9 \end{gathered}$

Slope of given equation is m= 25.9 it represents that,

People in this region spent an average of 25.9 daily minutes on their mobile devices from 2007 to 2014 .