STAT 5031
Homework 7 Solutions
Written Ex. 1.
The means are in-control = 10, out-of-control = 12, standard deviation = 2. Turning the out -of-control mean
into a Z score gives (12-10)/2 = 1. So we need a reference value of 0.5 on the standard scale. To ge
STAT 5031
Homework 5 Solutions
For the followup, we want to try to evaluate the ARL while the process is in control, and following inc reases of
50%, 100% and 200%. We can make life a bit easier working with (n-1)(S/. The cutoff for this is (42
2
1)*(30.9
Name .STAT 5031, first in-term test Page 1 of 3
STAT 5031 Statistical Methods for Quality Improvement Hawkins
Sample first interm test Time 50 minutes
Write your answers in the space provided. If this is not enough, continue on the back of the sheet or us
Name .STAT 5031, first in-term test Page 1 of 3
STAT 5031 Statistical Methods for Quality Improvement Hawkins
Sample first in-term test Time 50 minutes
Write your answers in the space provided. If this is not enough, continue on the back of the sheet or u
STAT 5031
Homework 4 Solutions
Lab portion.
muhat and sigmahat are 6.2952 and 0.0544 respectively.
The natural tolerance limits are 6.2952 + 3*0.0544 = 6.132 to 6.458. (As I multiplied the numbers by 100, is we
wanted them back on the original scale wed h
STAT 5031
Homework 3 Solutions
Extra part.
Here we have s = 0.999, n = 16. Given these the 95% confidence interval for
2 will be
[
(
)
(
)
] = [0.54, 2.39]
will be
[
(
)
(
)
] = [0.74, 1.55]
Extra problem.
>
>
>
>
>
n = 16
C = sqrt(qchisq(.95,n-1)/(n-1)
STAT 5031
Homework 2 Solutions
Continued part: The first part calculates the probability of non-conforming units EXCEEDING 0, 1, 2 or
3. This part calculates the probabilities of getting EXACTLY those numbers of non-conforming units.
In general, the proba