The subgroup sample sizes vary between 3 and 7. data wire; input day size @; informat day date7.; format day date7.; do i=1 to size; input brstr @@; output; end; drop i size; label brstr ='Breaking ...
and the variable SAMPSIZE contains the lot sample size. The following statements request an np chart for this data: title 'Number of Battery Failures'; symbol v=dot c=yellow w=1; proc shewhart ...