Exam 14: Business Analytics

SCENARIO 15-3 A quality control analyst for a light bulb manufacturer is concerned that the time it takes to produce a batch of light bulbs is too erratic.Accordingly, the analyst randomly surveys 10 production periods each day for 14 days and records the sample mean and range for each day. 1 58.5 5.1 2 47.6 7.8 3 64.3 6.1 4 60.6 5.7 5 63.7 6.2 6 57.5 6.0 7 55.0 5.4 8 54.9 6.1 9 55.0 5.9 10 62.7 5.0 11 61.9 7.1 12 60.0 6.5 13 58.3 5.9 14 52.0 5.2 -Referring to SCENARIO 15-3, suppose the analyst constructs an X chart to see if the production process is in-control.What is the upper control limit (UCL) for this chart?

Common causes of variation represent variation due to the inherent variability in the system.

SCENARIO 14-1 The table below contains the sparklines for the rates of return (in percentage) for three different stocks from 2007 to 2013. -Referring to SCENARIO 14-1, the sparklines enable you to draw conclusions on the historical trend of the rates of return of the three stocks.

SCENARIO 15-7 A supplier of silicone sheets for producers of computer chips wants to evaluate her manufacturing process.She takes samples of size 5 from each day's output and counts the number of blemishes on each silicone sheet.The results from 20 days of such evaluations are presented below. She also decides that the upper specification limit is 10 blemishes. -Referring to SCENARIO 15-7, an R chart is to be constructed for the number of blemishes.One way to create the lower control limit involves multiplying the mean of the sample ranges by D3.For this data set, the value of D3 is .

SCENARIO 15-4 A factory supervisor is concerned that the time it takes workers to complete an important production task (measured in seconds) is too erratic and adversely affects expected profits.The supervisor proceeds by randomly sampling 5 individuals per hour for a period of 10 hours.The sample mean and range for each hour are listed below. 1 18.4 25 2 16.9 27 3 23.0 30 4 21.2 23 5 21.0 24 6 24.0 25 7 19.3 12 8 15.8 14 9 20.0 13 10 23.0 11 She also decides that lower and upper specification limit for the critical-to-quality variable should be 10 and 30 seconds, respectively. -Referring to SCENARIO 15-4, what percentage of the time it takes workers to complete an important production task will fall inside the specification limits?

SCENARIO 15-1 A local newspaper has 10 delivery boys who each deliver the morning paper to 50 customers every day.The owner decides to record the number of papers delivered on time for a 10-day period for one of the delivery boys and construct a p chart to see whether the percentage is too erratic. Day Number of Papers DeliveredonTime 1 46 2 45 3 46 4 45 5 43 6 48 7 46 8 49 9 48 10 47 -Referring to SCENARIO 15-1, what is the numerical value of the upper control limit for the pchart?

In real-world business analytics, filtering is typically performed on large data based on complex conditional relationships.

Being able to monitor business activities in near real time is a feature most associated with:

Which of the following is NOT among the predictive analytics methods covered in the book?

SCENARIO 15-5 A manufacturer of computer disks took samples of 240 disks on 15 consecutive days.The number of disks with bad sectors was determined for each of these samples.The results are in the table that follows. \% 1 9 0.037500 2 7 0.029167 3 4 0.016667 4 6 0.025000 5 8 0.033333 6 3 0.012500 7 6 0.025000 8 10 0.041667 9 16 0.066667 10 24 0.100000 11 15 0.062500 12 9 0.037500 13 4 0.016667 14 8 0.033333 15 6 0.025000 -Referring to SCENARIO 15-5, a p control chart is to be made for these data.The estimate of the standard error of the proportion of disks with bad sectors is .

You can compute any of the numerical descriptive statistics for the variables of the new worksheet that a drill-down in a PivotTable creates.

In k-means clustering, observations that are assigned to a cluster may never be reassigned to a different cluster later in the process.

SCENARIO 14-4 The regression tree below was obtained for predicting the weekend box office revenue of a newly released movie (in thousands of dollars) based on data collected in different cities on the expenditure (at $25, $30, $35, $40, $45, $50, $55, $60, $65 or $70 thousand) spent on TV advertising and the number of times (10, 15, 20, 25, 30 or 35) a day the advertisement appear on TV. -Referring to SCENARIO 14-4, the highest mean weekend box office revenue is predicted to occur with $55 thousands spent on TV advertisement and 35 advertisement appearances a day.

A process is said to be out of control if

SCENARIO 14-2 The treemap below shows the amounts (size) measured in billions of US dollars and percentage changes from prior year (color) of business-to-consumer ecommerce sales last year for North America, Asia Pacific, Western Europe, Central & Eastern Europe, Latin America, and Middle East & Africa. -Referring to SCENARIO 14-2, the Asia Pacific region has the largest amount of business-to-consumer ecommerce sales last year.

Treemaps that use color to represent the value of a second variable, thereby increasing the data density of the displays, is an example of chartjunk.

Successful implementation of a regression tree requires a method to provide prediction for the target variable at each of the nodes.

The R chart is a control chart used to monitor a process mean.

SCENARIO 15-9 The manufacturer of canned food constructed control charts and analyzed several quality characteristics.One characteristic of interest is the weight of the filled cans.The lower specification limit for weight is 2.95 pounds.The table below provides the range and mean of the weights of five cans tested every fifteen minutes during a day's production. Number XBar Range Number XBar Range 1 3.05072 0.0215 16 3.04646 0.073 2 3.01228 0.087 17 3.03868 0.0696 3 3.03558 0.0851 18 3.03338 0.0329 4 3.01014 0.0674 19 3.03322 0.0455 5 3.00858 0.0983 20 3.05078 0.0215 6 3.02704 0.0527 21 3.04808 0.0396 7 3.04268 0.0508 22 3.05348 0.0581 8 3.01052 0.0791 23 3.05516 0.0682 9 3.03464 0.0663 24 3.03426 0.0325 10 3.02034 0.0538 25 3.0516 0.0641 11 3.03764 0.0584 26 3.05562 0.0809 12 3.0409 0.0434 27 3.04402 0.0374 13 3.0519 0.0762 28 3.06458 0.0284 14 3.03994 0.0833 29 3.0544 0.0738 15 3.03788 0.0601 -Referring to SCENARIO 15-9, an X chart is to be used for the weight.One way to obtain the control limits is to take the grand mean and add and subtract the product of A2 times the mean of the sample ranges.For this data set, the value of A2 is .

CPL >1 implies that the process mean is more than 3 standard deviation away from the lower specification limit.