You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 40 bacteria reveals a sample mean of : 68 hours with a standard deviation of 3 : 4 hours. You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.6 hours at a 95% level of confidence. What sample size should you gather to achieve a 0.6 hour margin of error? Round your answer up to the nearest whole number. n= 16X bacteria