The percentage of hotel rates over 110 euros is

22. The percentage of hotel rates over 110 euros is approximately
A) 2.5%**
B) 50%
C) 95%
D) 99.7%
E) 32%
23. Corinthia Hotel London has a nightly rate of 90 euros. The corresponding z-score for
this hotel is about
24. Which of the following will decrease the width of a confidence interval (assuming that
everything else remains constant)?
25. A 95% confidence interval estimate can be interpreted to mean that

95% of them would include the true population mean somewhere within their interval.
B) we have 95% confidence that we have selected a sample whose interval does include
the population mean.
C) Both of the above.**
D) None of the above.

26. In an application to estimate the mean number of miles that downtown employees
commute to work roundtrip each day, the following information is given:
n = 20
= 4.33
s = 3.50
Based on this information, the upper limit for a 95 percent confidence interval estimate
for the true population mean is:
A) about 5.97 miles.**
B) about 7.83 miles.
C) nearly 12.0 miles.
D) about 5.86 miles.
27. In developing a confidence interval estimate for the population mean, the t-distribution is
used to obtain the critical value when:
28. An economist is interested in studying the incomes of consumers in a particular region.
The population standard deviation is known to be $1,000. A random sample of 50
individuals resulted in an average income of $15,000. What total sample size would the
economist need to use for a 95% confidence interval if the width of the interval should
not be more than $100?