$15.75
Step-by-step explanation:
From the question, we are informed that a storekeeper increased the price of hats by 5% and that the hat was originally priced at $15.00.
The new cost of the hat will be:
= $15.00 + (5% × $15.00)
= $15.00 + (5/100 × $15.00)
= $15.00 + (0.05 × $15.00)
= $15.00 + $0.75
= $15.75
The new cost of the hat is $15.75