The answer is 13. She has 23 coins and it equals $4.25. So, if she has 10 dimes, that would equal $1 and if she has 13 quarters, that would equal $3.25.
The population isn’t given to be approximately normal. And for the following question, "A convenience sample of forty people is taken from a population. Which of the following is a reason why you can not make a statistical inference on the population?" The answer is The wrong sampling method was used.