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Chapter 12: Hypothesis Tests – Large Samples
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̅
̅
√
or
̅
̅
√
for
30 and
30
D.R
: For a specified significance level
, reject the null hypothesis if
the computed test statistic value
is greater than
.
Conclusion
: ……….
Note:
This is a right-tailed test because the direction of the inequality sign
in the alternative hypothesis is to the right.
Example 12-13
: “
With the
National Retail Federationestimating that the
average family will spend $669.28 on clothes, shoes, supplies and
electronics, more retailers are clamoring for a share of those sales. That's
up 5 percent
from last year's $634.78,but still shy of
2012's high of $688.62.For students heading to college, that average balloons to $916.48 per family,
up 10 percent from $836.83 last year, for things like dorm furniture,
bedding, school supplies, electronics and other comforts.”
Source:
http://www.cleveland.com/business/index.ssf/2014/07/raise_your_hand_if_yo ure_ready_for_back-to- school_shopping_average_costs_up_5_to_669_per_family.htmlHaving viewed this web site and read the article, a researcher would like to
establish that on average, female college students spend more than male
students on shopping at the beginning of the semester.
Table 12-6
shows the
summary results of the study done by the researcher for a sample of male
and female students.
Assume that the distributions for both groups of the amount of money spent
at the beginning of the semester are normally distributed.