During an epidemic, the number of people who have never had the disease and who are not immune (they are susceptible) decreases exponentially according to the function f(x) = 15000e-^(0.05t) , where t is time in days. find the number of susceptible people at each time below.
at the beginning of the epidemic
after 14 days
after 21 days
after 5 weeks

Which equation represents a proportional relationship that has a constant of proportionality equal to 1/5

Asmall (but heavy) particle placed in a glass of water will follow a zigzag motion because the particle will bounce off of the water molecules it meets. this is called brownian motion. a physicist simulates this on a computer, by varying the distance a particle can travel (called the mean free length), on average, before it collides with a water molecule and assigning the change in motion to be one of 8 directions, each with a similar probability. by running the simulated particle (with the same mean free length) many times she determines that it should take 15 seconds, on average, for the particle to fall to the bottom, with a standard deviation of 1.5 seconds. next she lets a real particle fall through a glass of water and finds that it took 18 seconds. what does she conclude, and why?

Percent increase and decrease. original number: 45 new number: 18