How many of you are in 7th grade

Need to increase the numbers of customers i talk to daily by 20% how many customers do i need to talk to if i talk to a average of 8 customers per hour during an 8 hour shift

Evaluate the following expression 1/3^2

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?