The length of time a traffic signal stays green (nicknamed the green time) at a particular intersection follows a normal probability distribution with a mean of 200 seconds and the standard deviation of 10 seconds. Use this information to answer the following questions. Which of the following describes the derivation of the sampling distribution of the sample mean?
A) The means of a large number of samples of size n randomly selected from the population of green times are calculated and their probabilities are plotted.
B) A single sample of sufficiently large size is randomly selected from the population of green times and its probability is determined.
C) The standard deviations of a large number of samples of size n randomly selected from the population of green times are calculated and their probabilities are plotted.
D) The mean and median of a large randomly selected sample of green times are calculated. Depending on whether or not the population of green times is normally distributed, either the mean or the median is chosen as the best measurement of center.
Question 2
The amount of soda a dispensing machine pours into a 12-ounce can of soda follows a normal distribution with a standard deviation of 0.04 ounce. Every can that has more than 12.10 ounces of soda poured into it causes a spill and the can must go through a special cleaning process before it can be sold. What is the mean amount of soda the machine should dispense if the company wants to limit the percentage that must be cleaned because of spillage to 3?
A) 12.1868 ounces B) 12.0132 ounces C) 12.0248 ounces D) 12.1752 ounces