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Department Of Economics
Time Duration: One hour
and Political Sciences
Date : 17/11/2007
Mr : Ibrahem Abed
COMPUTER & DATA ANALYSIS MIDTERM EXAM 1
Student’s Name: ............................................................................Student ID #: ........................
Question1 (10 Points): True or false:
1-
(
) One Sample T Test command is used to test the hypotheses concerning the population mean.
2-
(
) Histogram is used for quantitative data.
3-
(
) Bar graph is used only for the quantitative data.
4-
(
) Variance is a measure of Variation.
5-
(
) Kurtosis is a measure of the general shape of the distribution.
6-
(
) A correlation coefficient assumes a value between 0 and +1
7-
(
) In a one-sided hypothesis test, the p-value is 0.025. This means that the null hypothesis would
be rejected at α = 0.05.
8-
(
) It is necessary to have equal sample sizes for the paired t test.
9-
(
) If the calculated value of the t statistic is positive, then there is evidence that the null
hypothesis is false.
10-
(
) If the null hypothesis is rejected for a two-tailed test at   0.5 , then it will also be rejected
for a one tailed hypothesis test at the same   0.5 .
1
Question 2 (5 Points): Choose the correct answer:
1- The positive square root of variance is:
(a) Range
(b) Std. Deviation
(c) Median
(d) Std. Error
2- All of the followings are measures of Central Tendency except:
(a) Mean
(b) Median
(c) Mode
(d) Range
3- One out of the followings is a nominal variable
(a) Hair color
(b) Age
(c) Academic Ranks
(d) Height
4- According to the Central Limit Theorem, the distribution of a sample mean approaches a normal
curve as:
(a) Sample size gets larger
(b) The parent population is normally distributed
(c) The variance for the population is known
(d) Sample size gets smaller
5- In Hypothesis testing we reject the null hypothesis when
(a) P value > alpha (α)
(b) P value < alpha (α)
(c) P value = alpha (α)
(d) Non of the above
2
Question 3 (15 Points)
This data represents the percentage of Gross Domestic Product (GDP)consumed within the country for the
given year
Results are given on the attached SPSS printout. Let α = .05.
Is there enough evidence to show that the Mean of the (GDP)less than 65?
a) (2 Points) State the null and alternative hypotheses in words.
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b) (5 Points) What assumptions must be made in order for the test results to be valid?
Do they hold? Explain using the SPSS results.
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c) (2 Points) Give the test statistic value.
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d) (3 Points) Find the p-value and write a statement interpreting it in this problem.
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e) (3 Points) State the decision in words.
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3
100
Frequency
80
60
40
20
Mean = 64.525
Std. Dev. = 8.1445
N = 1,378
0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
Real consumption % of GDP
One-Sample Statistics
N
Real consumption % of
GDP
1378
Mean
64.525
Std.
Deviation
Std. Error
Mean
8.1445
.2194
One-Sample Test
Test Value = 65
t
Real consumption % of
GDP
-2.166
df
1377
Sig. (2-tailed)
.030
Mean
Difference
-.4753
95% Confidence Interval
of the Difference
Lower
-.906
Upper
-.045
4