Students of a large university spend an average of $7 a day onlunch. The standard deviation of the expenditure is $2. A simplerandom sample of 25 students is taken. What is the probability thatthe sample mean will be at least $4? Jason spent $15 on his lunch.Explain, in terms of standard deviation, why his expenditure is notusual. Explain what information is given on a z table. For example,if a student calculated a z value of 2.77, what is the four-digitnumber on the z table that corresponds with that value? Whatexactly is that 4-digit number telling us? Explain why we use zformulas. Why don't we just leave the data alone? Why do weconvert? must show work
