Someone help on this plzzz

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

Dakota earned $7.50 in interest in account a and $18.75 in interest in account b after 15 months. if the simple interest rate is 4% for account a and 5% for account b, which account has the greater principal? explain. to make it a little easier, there is an image. good luck!

Ana drinks chocolate milk out of glasses that each holdof a liter. she has of a liter of chocolate milk in her refrigerator. 10 how many glasses of chocolate milk can she pour?