An unfair coin is weighted so that the expected number of tails before the first heads is 3. What is the standard deviation of the number of tails that come up before the first heads?​

The physical fitness of an athlete is often measured by how much oxygen the athlete takes in (which is recorded in milliliters per kilogram, ml/kg). the mean maximum oxygen uptake for elite athletes has been found to be 60 with a standard deviation of 7.2. assume that the distribution is approximately normal.

The ratios of boys to girls on a soccer league is 2: 5. if there are 28 boys, how many girls are playing soccer? extra points! will mark as brainiest asap

Robert has 78 tomatoes and 56 cucumbers he wants to plant them in equal rows how many in each row