#### Answer

(a) In 2003 there were 61.5 million pet dogs in the United States.
(b) $p(5)=66.3$

#### Work Step by Step

(a) In this case $t=0$ and $p(t)=61.5$. 0 years after 2003 is exactly 2003. Therefore a sentence of interpretation is:
In 2003 there were 61.5 million pet dogs in the United States.
(b) Here, there were 66.3 million pet dogs in 2008, which is 5 years after 2003. If we want to translate it to the function, $x$ represents the years after 2003, therefore $x=5$
$p(t)$ represents the number of pet dogs, in millions, therefore $p(t)=66.3$.
$p(5)=66.3$