Diana calculated that she spent about 7.5 x 104 seconds doing her math homework during October. Enter this time in standard notation.

Standard deviation of 19,29,21,22,23

How many liters of peroxide should be added to 12 liters of an 8% peroxide solution so that the resulting solution contains 16% peroxide?   original added new amount of peroxide 0.96 liters x 0.96 + x amount of solution 12 liters x 12 + x 0.18 liter 1.14 liters 1.92 liters 2.10 liters

The high temp today was 62°. when nighttime comes, the temp will drop 40°. by 4am the temp will drop an additional 40°. what is the temp at 4am?