Brad's mother says she was tested for HCG during her last two doctor visits. On March 21, her HCG level was 200 mlU/ml (milli-international units per milliliter). Two days later, her HCG
level was 392 mIU/ml.
a. Assuming that the model for HCG levels is of the form y = ab', write an equation that
models the growth of HCG for Brad's mother's pregnancy.