Chemists use pH to measure the acidalkaline nature of compou

Chemists use pH to measure the acid/alkaline nature of compounds. A large vat of mixed commercial chemicals is supposed to have a mean pH = 6.3 with a standard deviation = 1.9 pH. Assume a normal distribution for pH values. If a random sample of 10 readings in the vat is taken and the mean pH is computed. What is the probability that the mean pH x for these readings