These questions are giving me a hard time. Any help is appreciated. Thanks!!

1: The weight of corn chips dispensed into a 48 ounce bag by the dispensing machine has been identified as possessing a normal distribution with a mean of 48.5 ounces and a standard deviation of 0.2 ounces. What proportion of the 48 ounce bags contains more than the advertised 48 ounces of chips?

2: Before a new phone system was installed, the amount a company spent on personal calls followed a normal distribution with an average of $900 per month and a standard deviation of $50 per month. Refer to such expenses as PCE'S (personal call expenses). Using the distribution above, what is the probability that during a randomly selected month PCE'S were between $775.00 and $990.00?

3: Farmers often sell fruits and vegetables at roadside stands during the summer. One such roadside stand has daily demand for tomatoes that is approximately normal distributed with a mean of 134 tomatoes and a standard deviation of 30 tomatoes. How many tomatoes must be available on any given day so that there is only a 1.5% chance that all tomatoes will be sold?

4: Transportation officials tells us that 70% of drivers wear seat belts while driving. Find the probability that more than 579 drivers in a sample of 800 drivers wear seat belts. Hint: This is binomial distribution. Use normal distribution approximations.