Question

In: Operations Management

Problem 2: Number of defective tires produced in 20 batches of 100 units each is given...

Problem 2: Number of defective tires produced in 20 batches of 100 units each is given below.

2, 5, 7, 1, 3, 5, 9, 12, 16, 5, 9, 12, 2, 14, 4, 7, 6, 8, 9, 11

What control charts will be appropriate? Develop upper and lower control limits for such charts. The next batch of 100 units showed 12 defectives. Is the process in control?

Problem 3: Inspection of 12 car panels in a Mercury plant showed the following number of defects on each panel:

9, 4, 3, 17, 24, 12, 10, 25, 12, 34, 10, 10

What control charts will be appropriate? Develop upper and lower control limits for such charts. Suppose the next three panels showed no defect at all. Is this process out of control? Why or why not?

Expert Solution

1. P-CHART WOULD BE APPROPRIATE HERE.

Z = 3
SAMPLE SIZE = 100
NUMBER OF SAMPLES TAKEN = 20

P-BAR = TOTAL NUMBER OF DEFECTS / (SAMPLE SIZE * NUMBER OF SAMPLES = 147 / (100 * 20) = 0.0735
STDEV = SQRT((PBAR * (1 - PBAR)) / SAMPLE SIZE = SQRT((0.0735 * (1 - 0.0735)) / 100 = 0.0261

UCL = PBAR + (Z * STDEV) = 0.0735 + (3 * 0.0261) = 0.1518
LCL = PBAR - (Z * STDEV) = 0.0735 - (3 * 0.0261) = -0.0048, SINCE LCL IS NEGATIVE, LCL = 0

2. NO, SINCE 1 POINT IS OUTSIDE THE CONTROL LIMIT(OBSERVATION 9), THE PROCESS IS NOT IN STATISTICAL CONTROL.

2. C CHART IS APPROPRIATE HERE

Z = 3
TOTAL NUMBER OF DEFECTS = 170
NUMBER OF SAMPLES = 12

C-BAR = TOTAL NUMBER OF OBSERVATIONS / NUMBER OF SAMPLES = 170 / 12 = 14.1667

UCL = C-BAR + (Z * SQRT(C-BAR)) = 14.1667 + (3 * SQRT(14.1667)) = 25.46
LCL = C-BAR - (Z * SQRT(C-BAR)) = 14.1667 - (3 * SQRT(14.1667)) = 2.88

2. THE CHART IS OUT OF CONTROL BECAUSE OBSERVATION 10 IS OUTSIDE THE CONTROL LIMITS.

** Leaving a thumbs-up would really help me out. Let me know if you face any problems.

keosha answered 4 months ago

given that random samples of process A produced 10 defective and 30 good units, while process...

given that random samples of process A produced 10 defective and 30 good units, while process B produced 25 defectives out of 60 units. Using the Chi square test, what is the probability that the observed value of chi swuare could result under the hypothesis that both processes are operating at the same quality level?

The probability distribution of X, the number of defective tires on a randomly selected automobile checked...

The probability distribution of X, the number of defective tires on a randomly selected automobile checked at a certain station is given by the table. X 0 1 2 3 4 p(X) 0.54 0.16 0.06 0.04 0.2 Table 4: Distribution for defective tires Use excel to find the answers please! thank you Find a. E(X) = b. E(X2) = c. σX =

Number of units produced 30, 000 Number of units sold &nbsp

Number of units produced 30, 000 Number of units sold 28,000 Selling price $20 Beginning inventory 0 Fixed selling and administrative costs $ 20,000 Fixed manufacturing overhead $ 150,000 Direct materials cost per unit 2 Direct manufacturing labor 6 Variable manufacturing overhead per unit 4 Variable selling expenses per unit 2 FMOH per unit 5 1.Operating Income under Absorption method is 2.If Sales Revenue $560,000 then Gross Margin under Absorption method is 3.Cost of Goods Sold and Ending inventory under Absorption costing method are: 4.What is...

The number of defective items produced by a machine (Y) is known to be linearly related...

The number of defective items produced by a machine (Y) is known to be linearly related to the speed setting of the machine (X). Data is provided below. a) (3) Fit a linear regression function by ordinary least squares; obtain the residuals and plot the residuals against X. What does the residual plot suggest? b) (3) Plot the absolute value of the residuals and the squared residuals vs. X. Which plot has a better line? c) (4) Perform a weighted...

If the number of units produced exceeds the number of units sold, then net operating income...

If the number of units produced exceeds the number of units sold, then net operating income under absorption costing will: be equal to the net operating income under variable costing less total fixed manufacturing costs. be greater than net operating income under variable costing. be equal to the net operating income under variable costing. be equal to the net operating income under variable costing plus total fixed manufacturing costs. . A company produces a single product. Last year, fixed manufacturing...

11.7. Machine speed. The number of defective items produced by a machine (Y) is known to...

11.7. Machine speed. The number of defective items produced by a machine (Y) is known to be linearly related to the speed setting of the machine (X). The data below were collected from recent quality control records. #d. Estimate the variance function by regressing the squared residuals against-X, and then calculate the estimated weight for each case using (11.16b). #e. Using the estimated weights, obtain the weighted least squares estimates of f30 and th. Are the weighted least squares estimates...

Twenty samples with 100 units each were taken; with the following number of defectives in each...

Twenty samples with 100 units each were taken; with the following number of defectives in each respective sample: 11, 2, 7, 5, 6, 7, 8, 5, 3, 6, 4, 3, 5, 6, 2, 5, 0, 9, 10, and 8. Calculate the center line, upper control limit, and lower control limit for a 3s p-chart. (RE: As your starting point, recall that p-charts represent percentages of defects for samples.) Plot the points on the chart. Comment on whether the process is...

In a lot of 100 microcircuits, 20 are defective. Four microcircuits are chosen at random to...

In a lot of 100 microcircuits, 20 are defective. Four microcircuits are chosen at random to be tested. Let X denote the number of tested circuits that are defective. a. Identify the distribution of X , including any parameters, and find P(X = 2). You do not need to provide a decimal answer. b. If appropriate (check), estimate P(X = 2) using an appropriate method.

Consider the processes given in Example 3.3. Determine the number of batches that can

Consider the processes given in Example 3.3. Determine the number of batches that can be produced in a month (500 h) using a series of single product campaigns when the required number of batches for product A is twice that of either product B or product C.

Year 1 Year 2 Beginning FG inventory in units 100 ? Ø Units Produced 3,000 1,000...

Year 1 Year 2 Beginning FG inventory in units 100 ? Ø Units Produced 3,000 1,000 Units Sold 2,000 2,000 Sales $800,000 $800,000 Material Costs $210,000 $70,000 Variable Labor $66,000 $66,000 Variable Overhead $24,000 $8,000 Fixed Overhead $240,000 $240,000 Variable Selling & Administration $60,000 $60,000 Fixed Selling and Administrative Expense $120,000 $120,000 *Beginning Inventory costs per unit for Year 0 are identical to those for Year 1. Ø The amount of beginning inventory for Year 2 is missing. Please determine...