1. Jerry the salesman knows from experience he has a 20% chance of making a sale when calling on a customer. One morning he prepares to make ten calls.
On this morning, how many sales does he expect to make?
What is Jerry’s probability of making exactly three sales?
What is Jerry’s probability of making four or more sales?
What is the chance Jerry will make at least one sale on this morning?
2. A study at Schnuck’s supermarket revealed that between 4 p.m. and 5 p.m. on weekdays there is an average of one customer for each minute interval at the deli counter.
What is the probability that you visit Schnuck’s deli counter at this time and find no customers during a one minute interval?
What is the probability that you visit Schnuck’s deli counter during this time and find four customers during a one minute interval?
What is the probability that you visit Schnuck’s deli counter at this time and find no more than two customers during a five minute interval?
What is the probability that you visit Schnuck’s deli counter at this time and find at least four customer during afive minute interval?
What is the probability that you visit Schnuck’s deli counter at this time and two minutes elapse with no customer visits?
3. The weight of a “40 lb.” bag of Good Growth Landscape Mulch is uniformly distributed over the interval from 38.5 lbs. to 41.5 lbs.
What is the probability that a bag will weigh more than 41 pounds?
What is the probability that a bag of landscape mulch will weigh less than 39.5 pounds?
What is the probability that a bag of landscape mulch will weigh between 39 and 40 pounds?
4. Old Main Investment Service recommends the purchase of shares of Dollar Department Stores. Old Main estimates that, in one year, the price of the shares will be at x where x is a random variable which is normally distributed with mean of $20 and a standard deviation of $2.
What is the probability that in a year the shares will be selling for more than $20?
What is the probability that in a year the shares of Dollar Department stores will be selling for exactly $20?
What is the probability that in a year the shares of Dollar Department stores will be selling for less than $18?
5. Suppose that the number of ounces of soda put into a Pepsi can is normally distributed with µ =12.05 ounces and σ = 0.03 ounces.
Legally, a can must contain at least 12 ounces of soda. What percentage of cans will contain at least 12 ounces of soda?
What percentage of Pepsi cans will contain less than 11.9 ounces of soda?
What percentage of Pepsi cans will contain between 12 ounces and 12.08 ounces of soda?
One percent of all Pepsi soda cans will weigh more than what amount?
Ten percent of all Pepsi cans will weigh less than what amount?
Pepsi controls the mean weight in a can by a weight setting on the machine filling the cans. For what mean should the machine be set so that only 1 in a 1,000 cans will be underweight (less than 12 ounces)?
