S
1
=
6.98
S
2
=
4.53
Private colleges mean = 35.5
Public colleges mean =22.3
21.3
c.
What is the point estimate of the difference between the two population means? Round your
answer to one decimal place.
42.5 – 22.3 = 20.2
=20.2
Interpret this value in terms of the annual cost of attending private and public colleges.
$20,200
c.
Develop a 95% confidence interval of the difference between the annual cost of attending private
and pubic colleges.
95% confidence interval, private colleges have a population mean annual cost $ to $ more expensive
than public colleges.
DID NOT GET ANSWER FOR C

8) .
Periodically, Merrill Lynch customers are asked to evaluate Merrill Lynch
financial consultants and services. Higher ratings on the client satisfaction
survey indicate better service with 7 the maximum service rating.
Independent samples of service ratings for two financial consultants are
summarized here. Consultant A has 10 years of experience, whereas
consultant B has 1 year of experience. Use = .05 and test to see whether
the consultant with more experience has the higher population mean service
rating.
Excel File:
data10-17.xls
a.
State the null and alternative hypotheses.
HO: MU1 – MU2 IS LESS THAN OR EQUAL TO 0
Ha : Mu1 – Mu2 is greater than 0
b.
Compute the value of the test statistic. (to 2 decimals)
1.99
c.
What is the
p
-value? (to 4 decimals)
.025 <p< .05 … I think…
d.
What is your conclusion?
Reject the null hypothesis

9)
Bank of America's Consumer Spending Survey collected data on
annual credit card charges in seven different categories of
expenditures: transportation, groceries, dining out, household
expenses, home furnishings, apparel, and entertainment. Using
data from a sample of 42 credit card accounts, assume that each
account was used to identify the annual credit card charges for
groceries (population 1) and the annual credit card charges for
dining out (population 2). Using the difference data, the sample
mean difference was = $850, and the sample standard deviation
was = $1123.
a.
Formulate the null and alternative hypotheses to test for no
difference between the population mean credit card charges
for groceries and the population mean credit card charges
for dining out.
: - Select your answer -mu is greater than 0mu is greater
than or
equal to
0mu is equal to 0mu
is not equal
to 0mu is
less than 0mu is less than or equal to 0Item 1
: - Select your answer -mu is greater than 0mu is greater
than or equal to 0mu is equal to 0mu
is not equal to
0mu is
less than 0mu is less than or equal to 0Item 2
b.
Use a .05 level of significance. Can you conclude that the
population means differ?
DIFFER

What is the
p
-value? (to 0 decimals)
sample
n = 42
difference=$850
sd=$1123
DID NOT GET ANSWER
c.
Which category, groceries or dining out, has a higher
population mean annual credit card charge?
GROCERIES
What is the point estimate of the difference between the
population means? (to 0 decimals)
850
What is the 95% confidence interval estimate of the difference
between the population means?

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