Business Statistics – Week #6 Assignment
Professor
Nord stated that the mean score on the final exam from all the years he has
been teaching is a 79%. Colby was in his most recent class, and his
class’s mean score on the final exam was 82%. Colby decided to run a
hypothesis test to determine if the mean score of his class was significantly
greater than the mean score of the population. α = .01.
·
What is the mean score of the population?
·
What is the mean score of the sample?
·
Is this test onetailed or twotailed? Why?
·
What is the null hypothesis in this case?
·
If p = 0.29, should Colby reject or fail to reject the null
hypothesis?
·
What should Colby’s statement of conclusion be? (This
circles back to what is being tested).
The
next two ask you do to a hypothesis test. Remember, hypothesis tests follow a
series of steps. They are not just a computer printout. Make sure if you
use a computer printout, you identify which parts of the printout apply to the
problem. All of the parts of the printout will NOT apply.
Question 2
A
sample of 22 account balances of a credit company showed a mean customer
balance of $4,300, but the marketing manager claimed that the mean balance for
the population was $4450. The marketing manager did NOT have the
population standard deviation, but the sample standard deviation was found to
be $400. Use the pvalue approach to conduct a full hypothesis test(all steps) that can be used to determine whether the
mean of all account balances is significantly different from $4440.
Let α = .05.
A
sample of 150 homes for sale in ABC City showed a mean asking price of $233,000,
but the city claimed that the mean asking price for the population was
$255,000. The population standard deviation of all homes for sale was
$11,000. Use the pvalue approach to conduct a full hypothesis test (all
steps) that can be used to determine whether the mean asking price is
significantly less than $255,000. Let α = .10.
During
the recent primary elections, the democratic presidential candidate showed the
following preelection voter support in Alabama and Mississippi.
State 
Voters Surveyed 
Voters in favor
of Democratic Candidate 
Alabama 
710 
352 
Mississippi

915 
480 
We
want to determine whether or not the PROPORTIONS of voters favoring the
Democratic candidate were the same in both states. In other words, is the first
proportion (p1) the same as (p2)? What formula, from this week’s
Notations and Symbols, would be applicable in the hypothesis test? (Notice
you are not doing a hypothesis test – you are saying which formula applies).
Grading Criteria Assignments 
Maximum Points 
Meets or exceeds established
assignment criteria 
40 
Demonstrates an understanding
of lesson concepts 
20 
Clearly presents
wellreasoned ideas and concepts 
30 
Uses proper mechanics,
punctuation, sentence structure, and spelling 
10 
Total 
100 