A high-paced discount store in Los Angeles has noticed that checking errors have increased recently. They plan to use control charts with three standard deviation control limits to monitor the process. From previous sampling, they believe that the average number of errors is 5%. They decided to take a sample of 100 transactions over 10 days. The number of transactions in error for each day was 5, 7,6, 5, 6,4,6 3, 10, 8.

a. What is the center line for the p chart?
b. What is the upper control limit for a p chart?
c. What is happening to the process?

In a test for esp (extrasensory perception), a subject is told that cards only the experimenter can see contain either a star, a circle, a wave, or a square. as the experimenter looks at each of 20 cards in turn, the subject names the shape on the card. a subject who is just guessing has probability 0.25 of guessing correctly on each card. a. the count of correct guesses in 20 cards has a binomial distribution. what are n and p? b. what is the mean number of correct guesses in 20 cards for subjects who are just guessing? c. what is the probability of exactly 5 correct guesses in 20 cards if a subject is just guessing?