Like any other large firm, Thorndike Sports Equipment receives daily telephone calls in which customers either praise or complain about a Thorndike product. Luke Thorndike is especially sensitive about the number of complaint calls received daily. Twelve weeks ago, he asked the customer service department to keep a daily log of the number of telephoned complaints received each day. Just six weeks ago, Thorndike ads began carrying a toll-free number through which customers could inquire or comment about Thorndike products. The customer service department has just handed Luke a summary of the daily complaints over the past 60 business days. Luke has just handed it to Ted, who finds the daily totals shown in the table. The data listed below.

1. Assuming the daily number of calls to be Poisson distributed, construct a c-chart for the first 30 days. Using 3-sigma limits, were there any days in which the volume of complaints fell outside the limits?
2. If any unusually high or low days were identified in part 1, construct a new pair of 3-sigma limits based on the days that remain from the initial 30-day period.
3. Using the upper and lower limits identified in part 2, extend the c-chart to include days 31-60. Based on the 3-sigma limits in this chart, does it appear that the toll-free number has caused a shift in the daily number of complaints received?
4. 

Number of Number 0'! Number of Number 0'! Day Complaint Day Complaint Day Complaint Day Complaint 1 2 1 6 3 3 1 4 46 2 2 4 1 '3' 1 32 6 4? 2 3 1 1 8 1 33 4 43 6 4 T 1 9 I) 34 3 49 T 5 1 20 2 35 5 50 2 6 3 2 I 'I 36 5 51 5 1' D 22 5 37 3 52 9 B 2 23 3' 33 5 53 3 9 3 24 6 39 2 54 4 1 0 2 2 5 1 4D 4 5 5 2 1 'I 2 26 0 4 1 5 56 9 1 2 3 2 T 3 42 B 5 i" 3 13 D 28 3 43 3 58 3 14 3 29 3 44 5 59 10 1 5 9 30 2 45 2 60 T