To find the constant of proportionality in dollars per ticket, we can start by determining the price per individual ticket when a set of 3 tickets is sold for $5.00.
First, we find the cost of one ticket:
\[ \text{Cost per ticket} = \frac{\text{Total cost}}{\text{Number of tickets}} = \frac{5.00}{3} \]
Now, we perform the division:
\[ \frac{5.00}{3} \approx 1.6667 \]
Rounded to the nearest cent, this is:
\[ 1.67 \]
Thus, the constant of proportionality in dollars per ticket is \( \boxed{1.67} \).