A Pedro le dieron de aguinaldo el triple de lo que recibe de sueldo en un mes. Si pagó una deuda de $4500.00 y aún le quedaron $7500.00, ¿ cuál es el sueldo mensual que recibe ?
a) $3500.00
b) $6000.00
c) $4500.00
d) $5000.00
e) $4000.00

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?