DID NOT GET ANSWER
10)
The College Board SAT college entrance exam consists of three
parts: math, writing and critical reading (
The World
Almanac
2012). Sample data showing the math and writing scores
for a sample of twelve students who took the SAT follow. Click on
the webfile logo to reference the data.
a.
Use a .05 level of significance and test for a difference
between the population mean for the math scores and the
population mean for the writing scores. What is the test statistic?
Enter negative values as negative numbers. Round your answer
to two decimal places.
t
=
DID NOT GET ANSWER
What is the
p
value? Round your answer to four decimal places.
DID NOT GET ANSWER
c.
What is the point estimate of the difference between the
mean scores for the two tests?
25
What are the estimates of the population mean scores for the two
tests?
Math test
514
Writing test
489
Which test reports the higher mean score?
MATH TEST
11)
A manufacturer produces both a deluxe and a standard model of an automatic sander designed for
home use. Selling prices obtained from a sample of retail outlets follow.
Excel File:
data1027.xls
Round your answers to 2 decimal places.
a.
The manufacturer's suggested retail prices for the two models show a $10 price differential.
Use a .05 level of significance and test that the mean difference between the prices of the two
models is $10.
DO NOT REJECT THE NULL HYPOTHESES (HO=10)
b.
What is the 95% confidence interval for the difference between the mean prices of the two models?
(to 2 decimals)
to
DID NOT GET ANSWER TO B
12)
Consider the following results for independent samples taken from
two populations.
Sample 1
Sample 2
n
1
= 500
n
2
= 300
p
1
= 0.42
p
2
= 0.34
a.
What is the point estimate of the difference between the two
population proportions (to 2 decimals)?
P1 – P2 = 0.42 – 0.34 = .08
=.08
b.
Develop a 90% confidence interval for the difference between
the two population proportions (to 4 decimals).
to
POINT ESTIMATE (+/) MARGIN OF ERROR AKA Z VALUE *
STANDARD ERROR
Square root of ((.42(1.42) / 500)) + ((.34(1.34)/300))
Standard error =.0494
90% alpha Z= 1.645
1.645 * .0494 = .0813
point estimate (+/) .0813
= .0013 to .1613
INCORRECT
c.
Develop a 95% confidence interval for the difference between
the two population proportions (to 4 decimals).
to
.0494 * 1.96 = .0968
margin of error = 0.0968
.08 (+/) .0968 =
INCORRECT
13)
Consider the hypothesis test below.
H
0
:
p
1

p
2
0
H
a
:
p
1

p
2
> 0
The following results are for independent samples taken from the
two populations.
Sample 1
Sample 2
n
1
= 200
n
2
= 300
p
1
= 0.29
p
2
= 0.11
Use pooled estimator of
p
.
a.
What is the value of the test statistic (to 2 decimals)?
(200 * .29 + 300 * .11) / (200 + 300) = .182
USING ABOVE FORMULA
((.29.11) / SQUARE ROOT OF .182(1.182) (500)
Z VALUE=.0208
=.5080
b.
What is the
p
value (to 4 decimals)?
1  .5080 =.492
WRONG
c.
With = .05, what is your hypothesis testing conclusion?
Conclude the difference between the proportions is greater
than 0
14)
The Professional Golf Association (PGA) measured the putting
accuracy of professional golfers playing on the PGA Tour and the
best amateur golfers playing in the World Amateur Championship
(
Golf Magazine,
January 2007). A sample of 1075 6foot putts by
professional golfers found 688 made putts. A sample of 1200 6
foot putts by amateur golfers found 696 made putts.
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 Fall '14
 Statistics, Standard Deviation, Chapter 10, Null hypothesis, Statistical hypothesis testing, Cengage Learning, Cengage Now, Cengagenowchapter10, Cengagech10