THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION

Short Answer

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
A large department store records the number of returns per day in women's dresses for reasons such as wrong size;husband didn't like it,color,etc.The manager of the women's dresses department recalls from her statistics class in college that the Poisson distribution might describe such events.A random sample of 150 days is taken.The number of returns per day in the sample as well as the observed frequencies is shown in the table below:

She tests the hypothesis that returns per day are Poisson distributed with a population mean equal to 1.90.Her significance level is 0.05
-What are the appropriate degrees of freedom?