You are sampling items from a batch and plotting the results on a control chart. How will an increase in the number of items sample affect the value of the standard deviation used to set the control limit?

Related MCQs

• You conduct a hypothesis test and you observe values for the sample mean and sample standard deviation when n = 25 that do not lead to the rejection of Ho (null hypothesis). You calculate a p-value of 0.0667. What will happen to the p-value if you observe the same sample mean and standard deviation for a sample n>25?
• Consider the first method of p bar estimation where each sample is of varying size. If the 3rd sample has p bar =.01, and the sample size of the 3rd sample is 10, what will be the upper control limit for the 3rd sample?
• Consider that for a process s bar (average standard deviation of 50 samples each of size 4) is found to be 10.04. The value of c4 (corresponding to sample size of .4) is .92. What is the estimated value of process standard deviation?
• Assume the cholesterol levels in a certain population have mean μ = 200 and standard deviation σ = 24. The cholesterol levels for a random sample of n = 9 individuals are measured and the sample mean x-bar is determined. What is the z-score for a sample mean x = 180?
• In a double sampling plan, let d1 be the number of defects in the first sample and d2 be the number of defects in the second sample. Let c2 be the acceptance number for both samples. The condition for rejection is:
• Factory A produces 100 pieces of wooden legs used in manufacturing tables in 1 hour. The factory in total works for 3 hours. The quality manager decided to check the quality of the output by measuring the length of the legs (in cms). He decides to collect three samples (one for each hour). The sample size for each sample is fixed at 5. The data collected is present in the following table: What is the mean and range of leg length in sample 1?
• An acceptance control chart has limits that are based on the specification limits for the product rather than limits which differentiate between random and assignable causes. Under which if the following circumstance should a QC manager consider using an acceptance control chart?
• In case someone is interested in process standard deviation, he should construct the ______________ chart.
• In case someone is interested in process standard deviation, he should construct the ______________ chart.
• You carried out an ANOVA on a preliminary sample of data. You then collected additional data from the same groups; the difference being that the sample sizes for each group were increased by a factor of 10, and the within-group variability has decreased substantially. Which of the following statements is NOT correct?