Answer: D. 26.6 million phones per year
Step-by-step explanation:
Given: The equation [tex]y=26.6x-14.5[/tex] is used to model the worldwide smartphone sales (y) in millions, each year (x) for a given company in its first 7 years selling smartphones.
Here the slope of the linear function(coefficient of x) = 26.6
Since, slope is the rate of change of the variables.
Therefore,the annual increase in the smartphone sales over this time period= 26.6 millions phones per year.
OR
When x=1
[tex]y=26.6(1)-14.5=12.1[/tex]
When x=2
[tex]y=26.6(2)-14.5=53.2-14.5=38.7[/tex]
The annual increase = [tex]38.7-12.1=26.6[/tex]
hence, the annual increase in the smartphone sales over this time period= 26.6 millions.
