Can someone me on 23 a and b plz

Initially 100 milligrams of a radioactive substance was present. after 6 hours the mass had decreased by 4%. if the rate of decay is proportional to the amount of the substance present at time t, find the amount remaining after 24 hours. (round your answer to one decimal place.)

Create a data set with 8 points in it that has a mean of approximately 10 and a standard deviation of approximately 1.

What is the value of n in the equation -1/2(2n+4)+6=-9+4(2n+1)