Penicillin 200- Minutes after concentration injection (micrograms 150 per milliliter) 0 200 100- 5 152 10 118 50 15 93 20 74 5 10 15 Time (minutes) When a patient receives a penicillin injection, the kidneys begin removing the penicillin from the body. The tab and graph above show the penicillin concentration in a patient's bloodstream at 5-minute intervals for the 20 minutes immediately following a one-time penicillin injection. The penicillin concentration, in micrograms per milliliter, in the patient's bloodstream t minutes after the penicillin injection is modeled by the function P defined by P(t)=200b 5. If P approximates the values in the table to within 10 micrograms per milliliter, what is the value of b, rounded to the nearest tenth?