Originally Posted by lvleph

Since you are claiming others are wrong...
14 divided by 46 = 0.30435

0.30434 times 60 = 18.26 mph average speed

But why not be consistent and keep it to 4 significant figures like you have in the final answer?
14 divided by 46 = 0.3043

0.3043 times 60 = 18.26 mph average speed