A Quality Analyst wants to construct a control chart for determining whether four machines, all producing the same product, are under control with regard to a particular quality attribute. Accordingly, she inspected 1,000 units of output from each machine in random samples, with the following results:
Machine Total Defectives
#1 23
#2 15
#3 29
#4 13
What is the sample proportion of defectives for machine #1?
Select one of the following: