Given:
The cost price of the deck of cards is $72.78 dollars.
Mark up percent is 5%.
a) To find the amount of mark up:
So, we can write it as,
![\begin{gathered} 5\text{ \% of 72.78=}(5)/(100)*72.78 \\ =\text{ \$}3.639 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/2n84j7xghfbw0ttpn8b86loih0a4jvqxhk.png)
Thus, the amount of mark-up is $3.64 (rounded to the nearest hundredth).
b) To find the new price:
The new price = Cost price + Amount of mark up
So, we get,
![\begin{gathered} =72.78+3.64 \\ =76.42 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/jnriyeg6tagh8yklpplsrk0s2ttol585db.png)
Thus, the new price is $76.42.