The annual expenditures of a family of four on psychological counseling services average $420 with a standard deviation of $80. Assume that the expenditures have normal distribution

(a) what percentage of these expenditures is less than $350? (provide the figure rounded to four decimal places):

b) what percentage of these expenditures is greater than 400? (provide the figure rounded to four decimal places):

c) What is the annual expense if it represents the highest 10% of the expenses (provide data rounded to one decimal place)?

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