Question

How profitable are different sectors of the stock market? One
way to answer such a question is to examine profit as a percentage
of stockholder equity. A random sample of 35 retail stocks such as
Toys 'R' Us, Best Buy, and Gap was studied for
*x*_{1}, profit as a percentage of stockholder
equity. The result was *x*_{1} = 15.0. A random
sample of 38 utility (gas and electric) stocks such as Boston
Edison, Wisconsin Energy, and Texas Utilities was studied for
*x*_{2}, profit as a percentage of stockholder
equity. The result was *x*_{2} = 9.0. Assume that
*σ*_{1} = 4.6 and *σ*_{2} = 3.1.

(a) Categorize the problem below according to parameter being
estimated, proportion *p*, mean *μ*, difference of
means *μ*_{1} – *μ*_{2}, or
difference of proportions *p*_{1} –
*p*_{2}. Then solve the problem.

*p**μ*_{1} –
*μ*_{2} *p*_{1}
– *p*_{2}*μ*

(b) Let *μ*_{1} represent the population mean profit
as a percentage of stockholder equity for retail stocks, and let
*μ*_{2} represent the population mean profit as a
percentage of stockholder equity for utility stocks. Find a 95%
confidence interval for *μ*_{1} –
*μ*_{2}. (Use 1 decimal place.)

lower limit | |

upper limit |

(c) Examine the confidence interval and explain what it means in the context of this problem. Does the interval consist of numbers that are all positive? all negative? of different signs? At the 95% level of confidence, does it appear that the profit as a percentage of stockholder equity for retail stocks is higher than that for utility stocks?

Because the interval contains only positive numbers, we can say that the profit as a percentage of stockholder equity is higher for retail stocks.Because the interval contains both positive and negative numbers, we can not say that the profit as a percentage of stockholder equity is higher for retail stocks. We can not make any conclusions using this confidence interval.Because the interval contains only negative numbers, we can say that the profit as a percentage of stockholder equity is higher for utility stocks.

Answer #1

from the given data,

*x*1 = 15.0, *σ*1 = 4.6 , n1=35

*x*2 = 9.0, *σ*2 = 3.1 , n2=38

a)difference of means *μ*1 – *μ*2. option 1..

b)

at 95% level , z=1.96

Se=0.4615=0.46

CI=6(1.96*0.46)

CI=(5.1,6.9)

lower limit | 5.1 |

upper limit | 6.9 |

c)Because the interval contains only positive numbers, we can say that the profit as a percentage of stockholder equity is higher for retail stocks

How profitable are different sectors of the stock market? One
way to answer such a question is to examine profit as a percentage
of stockholder equity. A random sample of 31 retail stocks such as
Toys 'R' Us, Best Buy, and Gap was studied for x1, profit as a
percentage of stockholder equity. The result was x1 = 14.6. A
random sample of 31 utility (gas and electric) stocks such as
Boston Edison, Wisconsin Energy, and Texas Utilities was studied...

A study of parental empathy for sensitivity cues and baby
temperament (higher scores mean more empathy) was performed. Let
x1 be a random variable that represents the
score of a mother on an empathy test (as regards her baby). Let
x2 be the empathy score of a father. A random
sample of 31 mothers gave a sample mean of x1 =
69.55. Another random sample of 36 fathers gave
x2 = 59.00. Assume that σ1
= 10.71 and σ2 =...

A study of parental empathy for sensitivity cues and baby
temperament (higher scores mean more empathy) was performed. Let
x1 be a random variable that represents the
score of a mother on an empathy test (as regards her baby). Let
x2be the empathy score of a father. A random
sample of 37 mothers gave a sample mean of x1 =
67.00. Another random sample of 27 fathers gave
x2 = 61.04. Assume that σ1
= 10.92 and σ2 = 11.62....

A study of parental empathy for sensitivity cues and baby
temperament (higher scores mean more empathy) was performed. Let x1
be a random variable that represents the score of a mother on an
empathy test (as regards her baby). Let x2 be the empathy score of
a father. A random sample of 29 mothers gave a sample mean of x1 =
67.68. Another random sample of 34 fathers gave x2 = 60.36. Assume
that σ1 = 10.85 and σ2 =...

A study of parental empathy for sensitivity cues and baby
temperament (higher scores mean more empathy) was performed. Let
x1 be a random variable that represents the
score of a mother on an empathy test (as regards her baby). Let
x2 be the empathy score of a father. A random
sample of 27 mothers gave a sample mean of x1 =
69.21. Another random sample of 25 fathers gave
x2 = 60.53. Assume that σ1
= 11.97 and σ2 =...

A study of parental empathy for sensitivity cues and baby
temperament (higher scores mean more empathy) was performed. Let
x1 be a random variable that represents the
score of a mother on an empathy test (as regards her baby). Let
x2 be the empathy score of a father. A random
sample of 27 mothers gave a sample mean of x1 =
67.00. Another random sample of 26 fathers gave
x2 = 59.85. Assume that σ1
= 11.90 and σ2 =...

a.) A study of parental empathy for sensitivity cues and baby
temperament (higher scores mean more empathy) was performed. Let x1
be a random variable that represents the score of a mother on an
empathy test (as regards her baby). Let x2 be the empathy score of
a father. A random sample of 32 mothers gave a sample mean of x1 =
69.55. Another random sample of 35 fathers gave x2 = 59.51. Assume
that σ1 = 11.06 and σ2...

A random sample of 19 wolf litters in Ontario, Canada, gave an
average of x1 = 4.8 wolf pups per litter, with estimated sample
standard deviation s1 = 1.0. Another random sample of 10 wolf
litters in Finland gave an average of x2 = 3.0 wolf pups per
litter, with sample standard deviation s2 = 1.4. (a) Categorize the
problem below according to parameter being estimated, proportion p,
mean μ, difference of means μ1 – μ2, or difference of proportions...

A random sample of 17 adult male wolves from the Canadian
Northwest Territories gave an average weight x1 = 97.4 pounds with
estimated sample standard deviation s1 = 5.5 pounds. Another sample
of 22 adult male wolves from Alaska gave an average weight x2 =
89.6 pounds with estimated sample standard deviation s2 = 6.9
pounds. Please show all steps in getting the answer. Thanks
(a) Categorize the problem below according to parameter being
estimated, proportion p, mean μ, difference...

A random sample of 22 adult male wolves from the Canadian
Northwest Territories gave an average weight x1
= 96.0 pounds with estimated sample standard deviation
s1 = 5.7 pounds. Another sample of 28 adult
male wolves from Alaska gave an average weight
x2 = 88.0 pounds with estimated sample standard
deviation s2 = 6.2 pounds.
(a) Categorize the problem below according to parameter being
estimated, proportion p, mean μ, difference of
means μ1 – μ2, or
difference of proportions...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 7 minutes ago

asked 38 minutes ago

asked 48 minutes ago

asked 53 minutes ago

asked 56 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago