Question

Suppose you calculate “X bar bar” = 25 and “R bar” = 7.5 from 25 previous...

Suppose you calculate “X bar bar” = 25 and “R bar” = 7.5 from 25 previous samples of size 5 each. Assume the quality characteristic has a normal distribution and both the “X bar” and R charts show statistical control of the process. Specification limits are at 24 ± 7.

   c) Calculate the percentage of items outside the specification limits.

  d) Calculate the capability index. Comment on the capability of the process.

Homework Answers

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A Quality analyst is checking the process capability associated with the production of struts, specifically the...
A Quality analyst is checking the process capability associated with the production of struts, specifically the amount of torque used to tighten the fastener. Twenty five samples of size 4 have been taken. These were used to create X bar and R charts. The values for these charts are as follows: The upper and lower control limits for the X-bar chart are 75 Nm and 72.16 Nm respectively. X double bar is 73.58 Nm, R bar is 1.66. The specification...
The Slip-Ring Diameters (cm) – Each Sample consisted of 5 Observations to Calculate the X-Bar and...
The Slip-Ring Diameters (cm) – Each Sample consisted of 5 Observations to Calculate the X-Bar and R-Bar CONTROL Charts for each of the Sample Size. PRESUME each Sample Consisted of 8 Observations AND HAD THE SAME X-BAR & R-BAR AVERAGES!! (Slide 4-29; 2 RightHand Columns ONLY!!) Calculate Upper and Lower Control Limits for X-Bar R-Bar Graph the CONTROL Charts with the 10 Data Samples X-Bar R-Bar
Control charts for x bar and R with subgroup size=4 are used to monitor a normally...
Control charts for x bar and R with subgroup size=4 are used to monitor a normally distributed quality characteristic. The control charts parameter were: X bar chart UCL=813, x bar chart CL=800, x bar chart LCL=787. R chart UCL=46.98, R chart CL=20.59, R chart LCL=0, both charts exhibit control. If the process mean shift from 800 to 780. What is the probability of detecting this shift on or before the second sample? A. 0.9934 B. 0.9834 C. 0.9993 D. 0.9894...
A process is in statistical control with x ̅ = 39.7 and R ̅ = 2.5....
A process is in statistical control with x ̅ = 39.7 and R ̅ = 2.5. The control chart uses a sample size of n = 2. Specifications are at 40 ± 5. The quality characteristic is normally distributed. Estimate the potential capability of the process. Estimate the actual process capability. How much improvement could be made in process performance if the mean could be centered at the nominal value?
A hospital is using X bar and R charts to record the time it takes to...
A hospital is using X bar and R charts to record the time it takes to process account information. A sample of five applications is taken each day. The first four weeks’ (20 days’) data give the following values: X-double bar= 17 min, R bar = 7 min. If the upper and lower specification limits are 21 minutes and 13 minutes respectively, calculate Cp and Cpk. Interpret the indices
Bongo’s nut bar is produced at a highly automated facility.  One of the quality control factors is...
Bongo’s nut bar is produced at a highly automated facility.  One of the quality control factors is the weight of each bar.  Samples of 10 bars are taken regularly and adjustments are made based on the outcome of quality control process.  Average weights and ranges of the latest samples are reported as following: Sample Average weight (gram) Range 1 51 5 2 53 4 3 48 1 4 49 3 5 52 2 What is the upper control limit of X chart? 50.5...
Suppose that the sample means and ranges are calculated for 36 samples of size n =...
Suppose that the sample means and ranges are calculated for 36 samples of size n = 5 for a process that is considered under statistical control. Then the mean of the 36 sample means and ranges are calculated, yielding  20.50 and 5.60, respectively: Determine the value of the process capability index if the process specification limits are 20 +- 6  . Is the process capable?
The General Widgets Company (GWC) is interested in setting up x-bar and R charts, both with...
The General Widgets Company (GWC) is interested in setting up x-bar and R charts, both with 3 sigma control limits on the net weight of a 100 ounce widget. They have collected 100 samples using the sample size of 9 and found that ?̿=99.95 and ?̅=1.3464. However, they are planning on switching to a sample of size 4. a)Set up the x-bar chart for a sample of size 4. b)Set up the R chart for a sample of size 4....
Samples of n =5 units are taken from a process every hour. The x̄ and R̄...
Samples of n =5 units are taken from a process every hour. The x̄ and R̄ values for a particular quality characteristic are determined. After 25 samples have been collected, we calculate x̄ = 20 and R̄ = 4.56. (a) What are the three- sigma control limit for x̄ and R? (b) Both charts exhibit control. Estimate the process standard deviation. (c) Assume that the process output is normally distributed. If the specifications are 19 ± 5, what are your...
need answer to these true-false questions. 1-) When the sample size n is moderately large, say...
need answer to these true-false questions. 1-) When the sample size n is moderately large, say n > 10 or 12, x̅ and R charts are preferable to X̅ and s charts. 2-) If Cp >1, the process uses up more than 100% of the specification band 3-) An assumption in the performance properties of x̅ and R control charts is that the underlying distribution of the quality characteristic is normal. 4-) Average time to signal is the expected number...