a day care program has an average daily expense of $75.00. the standard deviation is $5.00. the owner takes a sample of 64 bills. what is the probability the mean of his sample will be between $70.00 and $80.00?

step 1. calculate a z-score for $70.00 -
step 2. give the probability for step 1. %
step 3. calculate the z-score for $80.00 +
step 4. give the probability for step 3. %
step 5. add the probabilities from steps 2& 4. %