Could someone please help me on this equation?

Samantha swam upstream for some distance in one hour. she then swam downstream the same river for the same distance in only 12 minutes. if the river flows at 4 mph, how fast can samantha swim in still water?

The conversion factor relating feet to meters is 1 ft=0.305 m. keep in mind that when using conversion factors, you want to make sure that like units cancel leaving you with the units you need. you have been told that a certain house is 164 m2 in area. how much is this in square feet?

Given the following sampling distribution of one mean with a sample size 49, from a normally distributed population,find the population standard deviation, o.79828588912497