Answer:
1) [tex]y=2(1+0.081)^x[/tex]
2) 6.4 billion.
Step-by-step explanation:
1) Let the model that is used to find online jewelry sales ( in billions ) after x years,
[tex]y=a(1+r)^x[/tex]
Let 2003 is the initial year,
That is, for 2003, x = 0,
The sales on 2003 is 2 billion, y = 2,
⇒ [tex]2=a(1+r)^0\implies a=2[/tex]
Now, in 2013 they were approximately 5.5 1 billion
i.e. if x = 13 then y = 5.51,
[tex]\implies 5.51 = a(1+r)^{13}[/tex]
[tex]5.51=2(1+r)^{13}[/tex]
With help of graphing calculator,
r = 0.081,
Hence, the model that represents the given scenario is,
[tex]y=2(1+0.081)^x[/tex]
2) For 2015, x = 15,
Hence, online jewelry sales for 2015 would be,
[tex]y=2(1+0.081)^{15}=6.43302745602\approx 6.4\text{ billion}[/tex]
