Lecture Review for Exam 3 Overheads
1. Using 16 measurements (in millimeters) of a critical dimension on a
random sample of auto engine crankshafts from a Normally distributed
population, we obtained the following 95% confidence interval estimate
for
μ
: (223.97, 224.03)
a.
What are the simple conditions for this confidence interval for
μ
?
b. What is the population about which we want to make an inference?
c. What is the parameter we estimated with this confidence interval?
d.
Using the information in parts b and c, interpret the confidence interval for
μ
in context.
e. The following are true/false statements about this interval:
i.
This interval tells us that reasonable values for
μ
are all numbers
between 223.97 and 224.03.
ii.
We are 95% confident that the value of the sample mean of the 16
measurements will be in the interval, (223.97, 224.03).
iii.
95% of the time, when sampling crankshafts from this process, we will
get the confidence interval, (223.97, 224.03).
iv.
95% of all possible crankshaft measurements will be in the interval,
(223.97, 224.03).
v.
The probability that the value for
μ
is in this 95% confidence interval,
(223.97, 224.03), is 0.95.
vi.
95% confidence
means that 95% of the time, we will get the value of
μ
in this confidence interval, (223.97, 224.03).
vii.
95% confidence
means that 95% of all possible random samples of 16
crankshafts will yield 95% confidence intervals for
μ
that actually
contain the value of
μ
.
viii.
95% confidence
means that using this 95% confidence interval
procedure for
μ
, we will obtain confidence intervals that actually
contain the value of
μ
for 95% of all such intervals.
ix.
We are 95% confident that the value of
x
is in the interval, (223.97,
224.03).
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document2.
Referring to 16 crankshaft measurements described in question 1, the
process mean is supposed to be
μ
= 224. The sample standard deviation
is s = 0.060 mm.
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '10
 BRUCEJAYCOLLINGS
 Statistics, Normal Distribution, Standard Deviation, Statistical hypothesis testing, H0

Click to edit the document details