Question: A small, independent amusement park collects data on the number of cars with out-of-state license plates. The sample size is fixed at n=25 each day. Data from the previous 10 days indicate the following number of out-of-state license plates: Day Out-of-state Plates 1 6 2 4 3 5 4 7 5 8 6 3 7 4 8 5 9 3 10 2
a. Calculate the overall proportion of "tourists" (cars with out-of-state plates) and the standard deviation of proportions.
b. Using 95% limits, calculate the LCL and UCL for these data.
c. Is the process under control? Explain.