Solved by verified expert :71. How
many customers out of the 200 sampled must have favored Coke in this case?
72. Using
a 5% significance level, can the marketing consultant conclude that the
proportion of customers who prefer Coca-Cola exceeds 50%? Explain your answer.
73. If
you were to use a 1% significance level, would the conclusion from part cchange? Explain your answer.
.
QUESTIONS 74 THROUGH 77 ARE BASED ON THE FOLLOWING INFORMATION:
The owner of a popular Internet-based auction site believes that more
than half of the people who sell items on her site are women. To test this hypothesis, the owner sampled
1000 customers who sale items on her site and she found that 53% of the
customers sampled were women. Some
calculations are shown in the table below
Sample proportion
0.53
Standard error of sample proportion
0.01578
Z test statistic
1.9008
p-value
0.0287
74. If
you were to conduct a hypothesis test to determine if greater than 50% of customers
who use this Internet-based site are women, would you conduct a one-tail or a
two-tail hypothesis test? Explain your
answer.
75. How
many customers out of the 1000 sampled must have been women in this case?
76. Using
a 5% significance level, can the owner of this site conclude that women make up
more than 50% of her customers? Explain
your answer.
77. If
you were to use a 1% significance level, would the conclusion from Question 76
change? Explain your answer.
QUESTIONS 78 THROUGH 82 ARE BASED ON THE FOLLOWING INFORMATION:
Q-Mart is interested in comparing customer who used it own charge
card with those who use other types of credit cards. Q-Mart would like to know if customers who
use the Q-Mart card spend more money per visit, on average, than customers who
use some other type of credit card. They
have collected information on a random sample of 38 charge customers and the
data is presented below. On average, the
person using a Q-Mart card spends $192.81 per visit and customers using another
type of card spend $104.47 per visit.
Summary statistics for two samples
Q-Mart
Other Charges
Sample
sizes
13
25
Sample
means
192.81
104.47
Sample
standard deviations
115.243
71.139
Test of difference=0
Sample
mean difference
88.34
Pooled
standard deviation
88.323
Std
error of difference
30.201
t-test
statistic
2.925
p-value
0.006
78. Given
the information above, what is and for this
comparison? Also, does this represent a
one-tailed or a two-tailed test? Explain
your answer.
79. What
are the degrees of freedom for the t-statistic
in this calculation? Explain how you
would calculate the degrees of freedom in this case.
80. What
is the assumption in this case that allows you to use the pooled standard
deviation for this confidence interval?
