You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 40 bacteria reveals a sample mean of x=78x=78hours with a standard deviation of s=6.6s=6.6 hours. You would like to estimate the mean lifespan for this species of bacteriato within a margin of error of 0.5 hours at a 95% level of confidence.

What sample size should you gather to achieve a 0.5 hour margin of error? Round your answerup to the nearest whole number.

n = bacteria