Parking II Suppose that, for budget planning purposes, the city in Exercise 18 needs a better estimate of the mean daily income from parking fees. a) Someone suggests that the city use its data to create a 95% confidence interval instead of the 90% interval first created. How would this interval be better for the city? (You need not actually create the new interval.) b) How would the 95% interval be worse for the planners? c) How could they achieve an interval estimate that would better serve their planning needs? d) How many days worth of data should they collect to have 95% confidence of estimating the true mean to within $3?

Chapter 18 Definitions Probability model- all possible outcomes Ex. If you toss a coin 3 times. What is the chance it lands on tails (2^3=8) ANSWER: 8 Sample space - unique outcome Ex. When tossing a coin a unique outcome would be either heads or tails. Sample space= head (H) Tails (T) Event - collection of outcome Probability Rules Rule 1 : probability must be a number between 0 and 1 Rule 2: all possible outcome must = 1 *if it passes both rules 1&2 it’s legitimate Rule 3 AKA compliment rule: if the question ask what is the probability that the event doesn’t occur Use this Formula: 1 - probability the event WILL Occur Probability = numerical (has to be a number) Ex. Probability of dog losing the race is .40, what is th