3 C 1500 The brain mass of a human fetus during a particular trimester can be accurately estimated from the circumference of the head by m(c) = 100 ,where m(c) is C the mass of the brain (in grams) and c is the circumference (in centimeters) of the head. (a) Estimate the brain mass of a fetus that has a head circumference of 25 cm. (b) Find the rate of change of the brain mass for a fetus that has a head circumference of 25 cm and interpret your result. (a) The brain mass of a fetus that has a head circumference of 25 cm is about g (Type an integer or decimal rounded to two decimal places as needed.)