CRA CDs Inc. wants the mean lengths of the “cuts” on a CD to
be 135...
CRA CDs Inc. wants the mean lengths of the “cuts” on a CD to
be 135 seconds (2 minutes and 15 seconds). This will allow the disk
jockeys to have plenty of time for commercials within each
10-minute segment. Assume the distribution of the length of the
cuts follows a normal distribution with a standard deviation of
eight seconds. Suppose that we select a sample of 16 cuts from
various CDs sold by CRA CDs Inc.
What can we say about the shape of the distribution of the
sample mean?
What is the standard error of the mean?
What percentage of the sample means will be greater than 140
seconds?
What percentage of the sample means will be greater than 128
seconds?
What percentage of the sample means will be greater than 128
but less than seconds?
Solutions
Expert Solution
Answer:
NOTE:: I HOPE
YOUR HAPPY WITH MY ANSWER....***PLEASE SUPPORT ME WITH YOUR
RATING...
***PLEASE GIVE
ME "LIKE"...ITS VERY IMPORTANT FOR ME NOW....PLEASE SUPPORT ME
....THANK YOU
CRA CDs Inc. wants the mean lengths of the “cuts” on a CD to be
128 seconds (2 minutes and 8 seconds). This will allow the disk
jockeys to have plenty of time for commercials within each
10-minute segment. Assume the distribution of the length of the
cuts follows a normal distribution with a standard deviation of
nine seconds. Suppose that we select a sample of 18 cuts from
various CDs sold by CRA CDs Inc. Use Appendix B.1 for...
The lengths of lumber a machine cuts are normally distributed
with a mean of
104
inches and a standard deviation of
0.6
inch.(a) What is the probability that a randomly selected board
cut by the machine has a length greater than
104.14
inches?(b) A sample of
42
boards is randomly selected. What is the probability that their
mean length is greater than
104.14
inches?
(a) The probability is
The lengths of lumber a machine cuts are normally distributed
with a mean of
106106
inches and a standard deviation of
0.40.4
inch.(a) What is the probability that a randomly selected board
cut by the machine has a length greater than
106.15106.15
inches?(b) A sample of
3535
boards is randomly selected. What is the probability that their
mean length is greater than
106.15106.15
inches?
(a) The probability is
nothing.
(Round to four decimal places as needed.)
The lengths of lumber a machine cuts are normally distributed
with a mean of 99 inches and a standard deviation of 0.5 inch. (a)
What is the probability that a randomly selected board cut by the
machine has a length greater than 99.11 inches? (b) A sample of
44 boards is randomly selected. What is the probability that their
mean length is greater than 99.11 inches?
A researcher wants to test whether the mean lengths of two
species of trout are the same. He obtains the weights of 10
individuals of species A and 10 individuals of species B. The
sample mean weights are 12.3 kg and 14.3 kg, respectively, and the
sample variances are 3.5 kg2 and 4.5kg2.
Assume that the lengths are normally distributed.
a. Should we retain the hypothesis that the population variances
are equal?
b. Should we retain the hypothesis that the...
The table below shows the lengths of some randomly chosen CDs in
John’s very large collection. Give the 92% confidence interval for
the population mean, assuming that the population is approximately
normally distributed. Round the endpoints to two decimal
places.
69.33
74.64
65.28
61.01
38.52
69.07
40.01
42.14
41.52
56.76
58.14
70.80
39.21
71.36
46.94
52.90
56.16
41.01
56.57
60.97
64.62
69.12
66.58
58.26
62.79
Confidence interval: ( , )
John measured the total playing time of 30 randomly chosen...
The table below shows the lengths of some randomly chosen CDs in
John’s very large collection. Give the 92% confidence interval for
the population mean, assuming that the population is approximately
normally distributed. Round the endpoints to two decimal
places.
69.33
74.64
65.28
61.01
38.52
69.07
40.01
42.14
41.52
56.76
58.14
70.80
39.21
71.36
46.94
52.90
56.16
41.01
56.57
60.97
64.62
69.12
66.58
58.26
62.79
Confidence interval:
Assume that lengths of newborn babies follow a normal
distribution with mean μ. The lengths (in centimeters) of seven
randomly selected newborn babies are :45、46、59、53、46、51、54
(give answer to TWO places past decimal)
1. Construct a 99% confidence interval for μ: Lower Bound?,
Upper Bound: ?
2. Perform a hypothesis test to see if the population mean
length is more than 50 centimeters (HA : μ > 50) at the
significant level α = 0.05:
Compute the test statistic:_____
Indicate the...
Claudio Audio has $1000 which he can spend on either CD players
or CDs. He
cannot play his CDs without the CD player, but additional CD
players don't make him any
happier, since he can listen to only one at a time. CD players cost
$400 each; and CDs cost $10
each.
a. Write down the equation for Claudio's budget line.
b. Describe in words and math Claudio’s consumer problem.
c. Sketch in Claudio's indifference curves, with CD players on...
Suppose Bethany buys both CDs and video games. The price of a CD
is $15 and the price of a video game is $30. Suppose that given
Bethany’s planned expenditures, she receives 900 utils from her
last planned purchase of CDs and 1,200 utils from her last planned
purchase of video games. Is she at the optimal combination of CDs
and video games? Explain. If not, explain how she should alter her
consumption bundle. (Hint: use Marginal utilities and prices...