7. The mean production in a certain factory is 10 products per hour with a standard deviation of 1.5 products per hour. What is the probability of finishing more than 12 products per hour? 8. The average battery life of a cellphone is 25 hours with a standard deviation of 5 hours. If it follows a normal distribution, how many hours should be the cut-off in selecting the best 10% in terms of usage time? 9. A company's profit follows a normal distribution with a mean of Php 500,000 a month and a standard deviation of Php 50,000. What will be the company's lowest 20% possible profit? 10. The average net sales per year of the products in 60 branches of the DG Company is Php 85 million with a standard deviation of P15 million. Determine how many branches have a sale of Php 60 million to Php 85 million