Writing a conclusion about data shown in Xbar and R control charts

The exercise gives you 30 groups of 5 numbers each. You have to build a table indicating the Xbar, Xbar bar, R, Rbar, LCLx, UCLx and UCLr. Next thing is to plot the two graphs. I don't know the exact translation (I'm from Brazil) but they seem to be called x̅ and R charts. One of them is a graph consisting in 4 variables: Xbar, Xbar bar, LCL and UCL. The another one consists in 3: R, Rbar and UCL.

Last thing in the exercise is to write a conclusion about the graphs. There's no background to data, it represents a random process somewhere. I'm pretty sure I got the table and the graphs right because it's because just formulas, but I need a trusted conclusion about them. Both graphs show the same process so it's only one conclusion.

To clarify: the question is only about reading the graphs and writing a conclusion (3-4 lines, really basic), I explained the rest as context.

  • Low bounty!

  • I thought it was two or three minute work for someone who knows... What do you suggest as a bounty?

  • This is not my area of expertise, but I am sure it would take way more than 2-3 minutes to understand this problem and write a good conclusion. Offer whatever you think is fair, hopefully it will get answered by someone else.


Answers can be viewed only if
  1. The questioner was satisfied and accepted the answer, or
  2. The answer was disputed, but the judge evaluated it as 100% correct.
View the answer
  • Thank you for your answer and specially for pointing that out on 28! I wouldn't have realized it on my own.

The answer is accepted.
Join Matchmaticians Affiliate Marketing Program to earn up to 50% commission on every question your affiliated users ask or answer.