# Statistic Decision Making Final Exam

**Topics:**Statistics, Null hypothesis, Statistical hypothesis testing

**Pages:**2 (372 words)

**Published:**March 29, 2013

The information can be summarized as follows:

N1= N2

Standard Deviation= 15

Difference in Performance= 5

Power= .8

After entering the given information, the window looks as follows, which shows us that N1= N2= 142

In the window above, change the power to .9, then N1= N2 = 190

In the window above, change the sigma1=15, sigma2=12, and don’t select Egual Sigmas checkbox, thus I get N1= N2= 156

In the window above, change the N1=200 (control group), N2=120 (testing group), and select Independent in Allocation, thus I get .9046 to be the power.

=((61-64.5)-(0))/√((16*16)/200+(13*13)/120) = (-3.5)/1.6396 = -2.1347 Critical Value: Zα/2= Z0.05/2= @qnorm(1-0.05/2)= 1.96

When comparing the test statistic to the critical value: Z=2.1347>1.96, we reject the null hypothesis. We can calculate the P-value using the EViews command:

Show @tdist (t, d.f)

In this EViews command, t stands for the appropriate test statistic and d.f are the degrees of freedom. The appropriate test statistic was calculated above, namely Z=2.1347. For the degrees of freedom, we can insert NA+NB-2. Show @tdist (2.1347, 318)= 0.03355

Since the P-value= 0.033550, and β1= 0.86361050000

ls price c assessval

Dependent Variable: PRICE

Method: Least Squares

Date: 01/21/13 Time: 16:07

Sample: 1 650 IF PRICE>50000

Included observations: 562

VariableCoefficientStd. Errort-StatisticProb.

C12314.913021.9884.0751030.0001

ASSESSVAL0.8230410.02269536.265460.0000

R-squared0.701363 Mean dependent var113069.1

Adjusted R-squared0.700829 S.D. dependent var51534.97

S.E. of regression28187.83 Akaike info criterion23.33472 Sum squared resid4.45E+11 Schwarz criterion23.35013

Log likelihood-6555.056 Hannan-Quinn criter.23.34074

F-statistic1315.184 Durbin-Watson stat1.337129

Prob(F-statistic)0.000000

Estimated intercept...

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