Study shows that teenagers spend on average $ 55.5 per month on fast food. with a standard deviation of $4.5. If their monthly spendings are approximately normally distributed, determine: The...

• Study shows that teenagers spend on average $ 55.5 per month on fast food. with a standard deviation of $4.5. If their monthly spendings are approximately normally distributed, determine:

• The probability that their monthly spending is between $56.5 and $58.5

• The spending that separates the top 30% of the spending from the bottom of the 70% of the spending. Round answer to one decimal place.

If 36 teenagers are randomly selected, what is the probability that the mean of their monthly spending is greater than $57.5?