A scientist is studying the effectiveness of 2 different antibiotics on the same strain of bacteria. He uses the same dose of each antibiotic and starts with the same initial bacteria count, in billions, in each petri dish. His results are shown in the tables below. Let x represent the time in hours.
Part A: What is the initial number of bacteria in each petri dish? Explain your answer.
Part B: What is the decay rate for each antibiotic? Explain your answer.
Part C: How many bacteria will be left in each petri dish after the time has reached 8 hours? Round to the nearest thousandth. Show your work.