solve a,b and c please

Problem\#1(4 pts ): The count of surface nonconformities in 1000 square meters of 20-kg kraft paper is given in the following table. Based on 20 rolls of kraft paper (1000 ft2 each), we found totally 180 nonformities. 3 We are using a c-chart for monitoring the process. (a) What are the 3-sigma control limits? Is the process stable? (b) What is the -risk for this c-control chart? (Note: Use Poisson Approximation) (c) What is the -risk if the average number of defects is actually 16 per roll of kraft paper? (Note: Use Poisson Approximation)