Flaps are made in Falde by a certain process. The hardness, in Brinell degree, of the fasteners is checked. A fastener whose hardness is less than 30 is rejected. The inspected parts are damaged during the essal process. So each sample consists of a single attachment. The following table presents the results for 20 fasteners.

A) Establish the appropriate control limits and draw the maps to carry out the statistical control of this process. (Supposition: The corocteric is distributed according to the normole law.)

b) Is the process under control? (Justify your answer)

c) Estimate the standard deviation of the process.

d) If the process is kept under control at this level, what is the percentage of parts that will not meet the specification limit?

Des attaches sont fabriquetes a raide d'un certain procede. La duret6, en degre Brinell, des attaches est verifile. Une attache dont la durete est inferieure a 30 est rejette. les pieces inspectifes sont endommagees lors du processus deswal. Alors, chanus dohs.... itue diune seule attache la ouk. itue statistique de ce proced controle appropries et tracer les cartes pour effectuer la maitrise b) Est-ce que le procdide est sous controle? (Justfier votre flponse) c) Estimer Fcart-type du procede. d) Si le procid est maintenu sous controle a ce niveau, quel est le pourcentage de pieces qui ne rencontreront pas la limite de specification