Students of a large university spend an average of $5 a day on lunch. The standard deviation of the expenditure is $3. A simple random sample of 36 students is taken.Considerx, the average expenditure of the sample.What isE(x) andVar(x)? what is the probability that a randomly picked student's expenditure is less than $6, that is, P(X<6)?what isthe probability that the mean expenditure of the sample is more than $5.5, that P(x>5.5)?