The salinity in the ocean is expressed in parts per thousand (ppt). During November 2008, the mean salinity in a region of the tropical Pacific Ocean was 34.95 ppt. Suppose the distribution of salinity is Normal and the variance is 0.27, and suppose a random sample of ocean water from this region is obtained.
What is the probability that the salinity is more than 35 ppt?
What is the probability that the salinity is less than 33.5 ppt?
A certain species of fish can only survive if the salinity is between 33 ppt and 35 ppt. What is
the probability that this species can survive in a randomly selected area?
Find a symmetric interval about the mean salinity such that 50% of all salinity levels lie in this interval.