helpQUESTION $2$:

A manufacturer of fishing line takes sample of $60$ lengths at regular intervals and counts the

number that break when subjected to a strain of $38$ Newton's. During a period when

production was satisfactory the results for ten samples were as fallows.

a$.$ What is estimated single standard deviation of the process?

b$.$ Draw a control chart for proportion defective showing center line $($CL$),$ upper control

limit $($UCL$),$ lower controllimit $($LCL$)$ and plotting the ten points. $($Using $2$ sigma

for calculation $)$

c$.$ What action would you recommend if the number breaking in the next sample was

$($i$)$ sample $=11$ while number breaking $=18$

$($ii$)$ sample $=11$ while number breaking $=2$

$($iii$)$ sample $=11$ while number breaking $=10$