Question

University Hospital has been concerned with the number of errors found in its billing statements to patients. An audit of 100 bills per week over the past 12 weeks revealed the following number of errors:

Develop control charts with *z* = 3: **(a)**
CL, **(b)** UCL, **(c)** LCL.
*(If the lower control limit is negative, round the LCL
to zero and all other**answers to 2
decimal places, e.g. 15.25.)*

*CL:*

*UCL:*

*LCL:*

Is the process in control?

Week |
Number of Errors |
||

1 | 4 | ||

2 | 5 | ||

3 | 6 | ||

4 | 6 | ||

5 | 3 | ||

6 | 2 | ||

7 | 6 | ||

8 | 7 | ||

9 | 3 | ||

10 | 4 | ||

11 | 3 | ||

12 | 4 |

Answer #1

To solve this given problem, we'll first find the mean and
standard deviation of the five samples through MS Excel functions
**Average** and **STDEV**
respectively

The mean of the given data = 4.42

The Standard deviation of the given data = 1.56

Sample size = n = 10

Since the required sigma level = 3

**UCL** = Mean + [3 x (SD / Sqrt(n)] = 4.42 + [3 x
(1.56/10)] = 4.89

**LCL** = Mean - [3 x (SD / Sqrt(n)] = 4.42 - [3 x
(1.56/10)] = 3.95

So the control limits are (3.95, 4.89)

Since, many values fall outside the control range of (3.95,
4.89), the process is **out of control**.

A production manager at a Contour Manufacturing plant has
inspected the number of defective plastic molds in five random
samples of 35 observations each. Following are the number of
defective molds found in each sample:
Construct a 3-sigma control chart (z = 3) with this information.
(If the lower control limit is negative, round the LCL
to zero and all other answers to 2 decimal places, e.g.
15.25.)
CL:
UCL:
LCL:
Sample
Number of
Defects
Number of
Observations
in Sample...

4a.) The management of a hotel is worried about the number of
customer complaints. A detail analysis shows the number of
complaints in 100 feedback per week over the past 12 weeks. a)
Develop control charts with z = 3. b) Is the process in
control?
Week
Number of complaints
1
4
2
5
3
6
4
6
5
3
6
2
7
6
8
7
9
3
10
4
11
3
12
4

A restaurant is improving its processes, and is currently
focusing on the final bill presented to customers. The manager
samples 50 bills per day for 12 days, and checks to see how many
are incorrect using a z-value of 3. [ Select ] Is the billing
process consistent (in other words, is it in control), or do
special cause events appear to be present? [ Select ] What is the
UCL? [ Select ] What is the LCL? Day Day...

A university is concerned about the presence of grade
inflation, which is defined as an increase in the average GPA of
the institution's students over time without a comparable increase
in academic standards. To investigate this phenomenon, the average
GPA for the student body was recorded over the past 11years, as
shown in the table to the right. Construct a 90% confidence
interval for the slope. LCL= UCL=
(Round to three decimal places as needed.)
Year GPA
1
3.07
2 ...

A university is concerned about the presence of
grade inflation, which is defined as an increase in the average GPA
of the institution's students over time without a comparable
increase in academic standards. To investigate this phenomenon, the
average GPA for the student body was recorded over the past 11
years, as shown in the table to the right. Construct a 90%
confidence interval for the regression slope.
Year
GPA
Year
GPA
1
3.08
7
3.08
2
2.88
8
2.98...

Based on your recommendations, Mr. Miller improved shop
operations and successfully reduced the number of customer
complaints. To maintain good service, Mr. Miller asked you to keep
monitoring the wait times of oil change customers
at the shop.
First, you decide to create an x-bar chart to
monitor the central tendency (i.e., mean). But you know that we
sometimes overlook a problem if we use only an x-bar chart.
Therefore, you decide to create an R-chart to
monitor the process...

Using samples of 200 credit card statements, an Auditor found
the following:
---Sample Number: 1 2
3 4
5 6 7 8
9 10 11
12 13 14 15
Number of Errors: 17 12
11 12 10 10
17 15
12 13
15 10
7 8 10
Determine lower and upper control limits for the fraction of
errors using three-sigma limits.
Question 8 options:
0 , .126
.017 , .101
.026 , .093
.009 , .109
None of the Above
The Quality Control...

As a hospital administrator of a large hospital, you are
concerned with the absenteeism among nurses' aides. The issue has
been raised by registered nurses, who feel they often have to
perform work normally done by their aides. To get the facts,
absenteeism data were gathered for the last three weeks, which is
considered a representative period for future conditions. After
taking random samples of 60 personnel files each day, the
following data were produced:
Day
Aides Absent
Day...

The data shows the number of weeks employed and the number of
errors made per day for a sample of assembly line workers.
Weeks (x)
Errors (y)
1
20
1
18
2
16
4
10
4
8
5
4
6
3
8
1
10
2
11
1
12
0
12
1
Develop a scatter plot. Describe the relationship
between weeks and errors.
Use a simple least square regression equation to predict the
number of errors. Is there a significant relationship between...

You are the newly appointed assistant administrator at a local
hospital, and your first project is to investigate the quality of
the patient meals put out by the food-service department. You
conducted a 10-day survey by submitting a simple questionnaire to
the 400 patients with each meal, asking that they simply check off
that the meal was either satisfactory or unsatisfactory. For
simplicity in this problem, assume that the response was 1,000
returned questionnaires from the 1,200 meals each day....

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 17 minutes ago

asked 43 minutes ago

asked 48 minutes ago

asked 1 hour ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 3 hours ago

asked 3 hours ago

asked 3 hours ago