RAA602S - REGRESSION ANALSIS AND ANALYSIS OF VARIANCE - 1ST OPP - NOVEMBER 2024


RAA602S - REGRESSION ANALSIS AND ANALYSIS OF VARIANCE - 1ST OPP - NOVEMBER 2024



1 Page 1

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p
nAm I BI A u nlVE RSITV
OF SCIEnCEAnDTECHnOLOGY
FacultoyfHealthN, atural
ResourceasndApplied
Sciences
Schoool f NaturalandApplied
Sciences
Departmentof Mathematics,
StatisticsandActuarialScience
13JacksonKaujeuaStreet
Private Bag13388
Windhoek
NAMIBIA
T: +264612072913
E: msas@nust.na
W: www.nust.na
QUALIFICATION: BACHELOR of SCIENCE IN APPLIED MATHEMATICS AND STATISTICS
QUALIFICATION CODE: 07BSAM
LEVEL:6
COURSE: REGRESSION ANALYSIS AND ANALYSIS OF
VARIANCE
DATE: NOVEMBER 2024
DURATION: 3 HOURS
COURSECODE: RAA602S
SESSION: 1
MARKS: 90
EXAMINER:
MODERATOR:
FIRSTOPPORTUNITY:EXAMINATION QUESTION PAPER
MR. ANDREW ROUX
DR. J. Mwanyekange
INSTRUCTIONS
1. Answer all questions on the separate answer sheet.
2. Please write neatly and legibly.
3. Do not use the left side margin of the exam paper. This must be allowed for the
examiner.
4. No books, notes and other additional aids are allowed.
5. Mark all answers clearly with their respective question numbers.
PERMISSIBLEMATERIALS;
1. Non-Programmable Calculator
ATTACHEMENTS
1. Statistical Formulae Sheet
2. F - & T - Distribution Table
This paper consists of 5 pages including this front page

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QUESTION 1
[32]
The chairman of the accounting department at a large university undertakes a study
to relate starting salary (y) after graduation for accounting majors to grade point
average (GPA) in major courses. To do this, records of seven recent accounting
graduates are randomly selected.
Accounting
Graduate
1
2
3
4
5
6
7
GPA
X
3.26
2.60
3.35
2.86
3.82
2.21
3.47
Starting Salary (y)
(Thousands of dollars)
28.2
24.8
27.9
25.3
30.3
23.0
29.4
/J /3 1.1) Compute the least squares point estimates of
and
O
1
1.2) Write the least squares prediction equation relating y to x
(4+4 = 8)
(2)
1.3) Calculate both the Sum Squares of Error SSE and the Mean Squares of Error
MSE
(4 + 2 = 6)
1.4) Calculate the variance of x, s.~ and the standard error of the slope s b,
(4 + 4 =8)
1.5) Test the slope obtained for a direct linear relationship (using a = 0.10)
(8)
QUESTION 2
[30]
The data below shows the number of ice creams (y) sold, country-wide, at ten outlets
x of Spar Supermarkets. The table below also indicates the impact of three ( Xi ; 2 ;
x 3 )factors affecting the sales of ice creams at those different outlets
Outlet
V
X1
X2
X3
1
730
152
198
91
2
760
173
201
81
3
850
166
202
69
4
840
161
202
72
5
720
152
198
91
6
730
153
205
91
REGRESSIONANALYSISAND ANALYSISOF VARIANCE(RAA602S)
1st opportunity November 2024
2

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7
840
166 204
70
8
730
157 204
90
9
650
136
172
47
10
850
142 218
59
11
740
151 207
88
12
720
145 209
60
13
710
147 190
63
SUMMARY
OUTPUT
Regression
Statistics
Multiple 0.85362
R
7
R
0.72868
Square
Adjusted 0.63823
R
9
Square
Standar 38.7825
d Error
9
ObseNa
13
tions
ANOVA
Regressio
n
Residual
Total
df
ss
3 36355.51
MS
F
Significance F
12118.5 8.057037 0.006439
9 13536.8 1504.089
12 49892.31
Intercept
X1
X2
X3
Coefficient
s
-372.984
3.536757
3.734544
-2.16607
Standard
Error
242.3717
1.194784
1.10691
0.85177
t Stat
-1.53889
2.960165
3.373845
-2.54302
P-value
0.158214
0.015955
0.008207
0.031554
Lower
95%
-921.267
0.833968
1.230539
-4.09291
Upper
95%
175.2991
6.239546
6.238549
-0.23923
Lower
95.0%
-921.267
0.833968
1.230539
-4.09291
Upper
95.0%
175.2991
6.239546
6.238549
-0.23923
Consult the "EXCEL SUMMARY OUTPUT' to answer the following questions below
2.1) Discuss the "Regression Statistics"
(10)
2.2) State the multiple regression model for this data set.
(3)
REGRESSIONANALYSISAND ANALYSISOF VARIANCE(RAA602S)
rt opportunity November 2024
3

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2.3) Test the validity of the model
( use a = 0.05)
(7)
2.4) Test to determine whether there is enough evidence to infer that there is a
linear relationship (gradient) between the maximum ice thickness (y), and the
"number of days per year of ice cover" ( x,) Use a= 0.10
(10)
QUESTION 3
[12)
A recent survey conducted by the Directorate of Rural Water Supply considered a
random sample of 49 farms in the Hardap Region , 45 farms in the Omaheke Region
and 29 farms in the Karas Region. The average rainfall recorded for September
2012 over those farms in the Hardap Region was found to be 8.36 mm, with a
standard deviation of 2.98 mm, while the average rainfall recorded over the farms in
the Omaheke Region was found to be 7.91 mm, with a standard deviation of 3.15
mm. The average rainfall recorded over the farms in the Karas Region was found to
be 9.02 mm with a standard deviation of 3.62 mm.
Use the following sample statistics to test a claim that there is NO difference in the
average rainfall over farms in these regions. ( use a = 0.05)
Question 4 [16)
A randomized block experiment produced the data below.
Blocks
Treatments
1
2
3
4
1
6
5
4
4
2
8
5
5
6
3
7
6
5
6
4.1) Can we infer at the 5% significance level that the treatment means differ? (8)
4.2) Can we infer at the 5% significance level that the block means differ?
(8)
XXXXXXXXXXXXXXXXXXXXENXDXXXXXXXXXXXXXXXXXXXXXXXXXX
REGRESSIONANALYSISAND ANALYSISOF VARIANCE(RAA602S)
1'1Opportunity November 2024
4

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FORMULAE SHEET
= n(Lxy)-(Lx)(LY)
n(Lx 2 )-(Lx) 2
0
= LY-.B(Lx)
n
MST
Fsw,= MSE
MST= SST
k-l
MSE = SSE
n-k
+ f3111X11
SE
MSE = SSE
n-2
REGRESSIONANALYSISAND ANALYSISOF VARIANCE(RAA602S)
1st Opportunity November 2024
5

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F-table 0.05
Table of F-statistics P=0.05
11~1~'1'1'141'1'1'1'1'FFF~FFFFFFFFFFFFFFFFFFFFFFFo} 000 I~~/ l>lOOO
~110.1319.ss 19.2819.1219la..0914la.89la.asla.a1la.79la.76la.74la.73la.71la.70Ja.69la.6ala.67Ja.67la.66la.6sla.64la.63Ja.62la.62la.60la.s91a.s9la.sala.s7la.s7la.s6la.ss1a.s4la.s31a.s3
~17.71 16.9l46.s916.3l69.26l6.1616.o916l.6o.4ools.96ls.94ls.91ls.89ls.87ls.86ls.84ls.831s.a2ls.a1ls.aols.79ls.77ls.76ls.7sls.7sls.73ls.72ls.71ls.7ols.69ls.Gals.67ls.66ls.GsJs.64ls.63fs.63~
rs--16.61 ls.79ls.41ls.19ls.os14.9514.1a4a.8124.7714.74141.47.06184.6614.64141.46.26l04.s914.s1a4.5174.5164.5414.1543.5214.Js4o.S1O4.4814.4614.4514.41344.4124.4124.414.3914.1347.37~rs--
~ls.99 ls.1414.7614.5314.3914.2814.2114.1514.10141.o36.91841.o33.91641.o3o.9413.9213.91131.39.081731.3a.a8613.8413.8313.8213.8113.79J3.7713.7613.7513.7413.7313.7213.7113.69J3.6813.6
~15.59 14.7414.3514.1213.9713.8713.7913.674313.16308.5713.5513.5313.45193.4183.4173.4163.4413.43131.34.14103.3913.3813.3613.3413.33131.33.21931.33.10239.2713.2513.2413.23
,1815.32 14.4614.0713.8413.61931.35.10538.4413.1339.3513.1331.2183.2613.1234.2213.1230.1193.1713.1613.1513.11331.3lo.1132.0913.1o3a.o613.lo34.o313.02131.021.9192_9192.9J72.9512.9142.93[2-9313
·~15.12 14.2513.85131.35.34183.3713.29131.32.31183.1143.1103.0173.o1s3.0133.012.9192.9172.9152.91s2.9142.9122.9l02.a912.a172.al52.a412.a132.a12.8102.7192.7182.7172.7152.7132.7122.71
110l4.96 J4.1013.713.4J83.3313.2213.1134.0713.1022.9J82.9412.912.8192.8162.als2.a3l2.a112.a1o2.7192.7172.71s2.7J42.7212.712.7J02.6a12.6J62.6512.5142.6122.612.6l02.s9J2.s612.ssl2.s4~jlO
11114.84 13.91B3.s913.36131.32.00913.102l.9152.9012.la2s.a212.7912.75J2.741122..772012.6912.6712.G515s2.6132.6J12.s912.sa12.5712.1525.s312.5l22.s112.4192.4182.4712.1426.4132.4J22.41lz.41111
11214.75 13.8193.4193.2613.1131.o1o2.912.8152.a1o2.71s2.7122.6192.6162.5142.6122.6102.sa12.5172.5l62.s412.5122.512.4l92.4a12.4172.4142.4132.412.4102.3182.3172.3l62.3s12.3122.312.30~112
11314.67 13.813.4l13.1B13.0132.9l22.a312.7172.712.6172.6132.6102.sa12.ssJ2.s3l2.s112.so12.4182.4172.4162.4142.4122.412_3J92.3BJ2.3612.3142.3132.312.3102.21a2.2172.2162.2J32.2212.21ju1113
~J4.60 J3.74J3.3413.112.9162.8152.7162.7102.G1s2.Gl2o.s712.5132.s1l2.4a12.4162.4142.4132.412.4102.3192.3l72.3s12.3132.3122.312.21a2.2172.21s2.2142.2122.212.2102.1J92.1GJ2.1412.14
j15J4.S4 13.6J83.29l3.0612.9102.7192.7J12.64J2.5912.5l42.s1J2.4aJ2.4s12.4122.4J02.3aJ2.3712.3152_34121.323.312.2192.2J72.2G12.21s2.2122.2102.1l92.1a12.1l62.1s12.1142.1J22.1012.o1a2.07~115
j16J4.49 13.6J33.24l3.0112.a1s2.7142.Gl2G.s9J2.s412.4192.4162.4J22.4o12.3l72.3s12.3J32.3212.3102.2192.2la2.2s12.2142.2122.212.1192.1172.11s2.1142.1122.112.0192.0182.0172.0142.0122.02~116
11714.45 13.5913.1220.9l62.a112.7102.612.ssJ2.49l2.4s12.412.3182.3152.3J32.312.2192.2172.2162.2142.2132.212.1192.1172.1512.112s.1122.1102.0192.o1a2.0162.o1s2.0132.0211.l9t.997lt.97 ~117
~14.41 13.ss13.1612.1923.7712.1626.5182.5J12.4612.412.3J72.3412.312.2192.2172.2152.2132.2122.2102.1J92.17l2.1sJ2.1312.1J22.112.o1a2.0162.0152.0412.0212lt..0909l1.9alt.95Jt.9311.92
11914.38 13.5213.J123.9o12.7412.l623.s4l2.4a12.4122.3182.3142.3l12.2a12.2J62.2312.212.2l02.1a12.1172.1162.1132.112.1102.o1a2.0172.o1s2.0132.012.0l0t.98lt.97lt.96lt.94Jt.91l1.a911.aa[1.ss119
rus-~ !2014.35 13.4913.l120.a712.7112.6102.5l12.4s12.3J92.3s12.312.21a2.2Js2.23J2.20l2.1a12.1J72.1s12.1142.1J22.1012.o1a2.0712.1o2s.0J42.011.9191.9l8t.97l1.9s11.9131.9121.911.ala1.a6Ji.as f1.ii4!20
~14.30 13.4413.1o2s.8122.6162.ssJ2.4612.4102_3142.3J02.2612.2132.2102.1172.11s2.1J32.112.1102.o1a2.0J72.os12.0132.0J12.oo11.9181.9J6t.94Jt.92Jt.91l1.a9Ji.as11.aJGi.asl1.a2Ji.soJ1.79
~14.26 J3.40J3.012.71a2.6l22.s112.4J22.3612.3102.21s2.2l22.1aJ2.1s12.1132.1J12.09J2.0712.o1s2.0142.0132.0l0t.9811.9l71.9s11.9141.9l11.a911.ala1.a6l1.a4l1.a3l1.a2It.solt.7711.71s1.74
12614.23 J3.37J2.9B12.7l42.s912.4172.3192.3122.2172.2l22.1al2.1s12.1122.0192.0J72.os12.0132.0J22.ooJ1.99lt.97l1.9s11.9131.9J11.90l1.a711.als1.a4l1.a211.alot.79l1.7a11.7161.7J31.711.70~126
12814.20 13.3l42.9s12.712.sG12.4152.3162.2192.2142.1l92.1s12.1122.0192.0152.0142.0122.0101.9191.9171.9161.9131.911.9101.ala1.a7l1.a4l1.a211.a1o1.7191.7l7t.75lt.74lt.7311.6l9t.6711.66fl.66128
!3014.17 13.3122.9122.6l92.s312.4122.3132.2172.212.1162.1132.0192.0162.0142.011.9l91.9a11.9l61.9s11.9131.9l11.a9l1.a7l1.a5l1.a4l1.a111.7191.7171.7611.7411.17.2711.7101.6161.6141.63f1.6213D
13514.12 13.2172.a172.6412.4912.3712.22912.16121.21.1oJa2.0412.011.9191.9161.9411.9211l1.9.a1911.a1a1.als1.a3l1.a211.8101.79J1.7611.7411.7J211.16.81710.GJG1.6s11.6131.6l01.s7J1.s7~135
~14.08 13.2132.a142.6l12.4s12.3l42.2sl2.1a12.1122.o1a2.0142.0101.9l71.9s11.9121.9l01.a9l1.a711.al1s.a4l1.a111.7191.7711.1716.7141.7121.6191.6171.6161.6141.6121.6l11.s9l1.5sl1.s3l1.s21151~
~14.06 13.2l02.a1J2.saJ2.42J2.31J2.22l2.1s12.1J02.osJ2.011.9J7l.9411.9l21.a9J1.a7J1.aGl1.a4J1.a2l1.a111.7181.7161.7J4i.7311.711.6181.6J61.64lt.6311.6101.5911.1517.5J5t.51Jt.49l1.4a
1
rso-14.03 13.1182.7l92.s6J2.4D12.2192.2102.1132.0172.0131.9l91.9sJ1.92l1.a9l1.a711.als1.a3l1.a111.alo1.7al1.7611.7411.lnt.7011.6191.6611.1613.611.6011.ls1a.s6l1.s4l1.s2J1.4al1.4Gfvis["L44""rso-
16Dl4.00 J3.1512.7J62.s312.3l72.2s12.1172.1102.0141.9l91.9s11.9J21.a9J1.aGl1.a4l1.a211.alo1.7a11.7l61.7sl1.72l1.70J1.6B11.6l61.6sJ1.62l1.s911.5171.sGJ1.s3l1.s211.sol1.4a11.4J41.41J1.40fu9!60
~J3.98 13.1J32.7412.5102.3152.2132.1142.0172.0121.9171.9J31.a9Ji.BGJ1.a4J1.a111.7191.7171.7l5t.7411.7121.7101.6J7t.6511.6141.6121.5J91.5711.5J51.5311.soJ1.4911.4171.4151.4J0l.37J1.36[Lis~
fsol3.96 13.112.7122.4192_3132.212.1132.0162.0l01.9s11.9J11.aal1.a4l1.a211.7J9i.7711.71s1.7131.7211.1710.G1a1.G1s1.6131.6121.Gl1o.s7l1.s4l1.s2l1.s111.4181.4l6t.4511.4J31.3Blus lu4 ~[so
j[loo13.94 13.0192.7102.4J62.31J2.1912.1J02.0311.9171.9J31.a911.als1.a211.7191.7J71.7sJ1.7311.7J11.69J1.6B11.G1s1.5131.6J11.59J1.s711.5l41.s211.4l9t.48J1.4s11.4311.1411.3J9l.34lu1 luo ~[loo
1J2ool3.89 13.0142.61s2.4122.2162.1142.0l61.9a11.9J3i.asJ1.a411.aJo1.7711.7141.n11.5J9l.6711.6161.6J41.G121.6l01.s711.5l51.s3l1.s2l1.4a11.4161.4J31.41lu9 11.3J61.3s11.3121.2161.2J21.21~jzoo
fsool3.a6 13.012.6212.1329.2132.1122.0311.1916.9101.als1.a111.7J7t.74lu1 11.6191.6161.6141.6121.6l11.s9l1.5611.s4111.512.5101.4Ja1.4511.4121.4101.3laus J1.3211.3J01.2aJ1.211.1161.14fu2Tsoo
J 100013.as13.o1o2.6J12.3a12.2122.112.0121.9l51.a9l1.a411.a1o1.7161.7131.7101.6l81.6s11.6311.1611.6l01.sal1.ssJ1.s3J1.s111.4191.4171.4131.4l1ua lu6 lu3 11.311.2J91.2G11.1J91.13
I 1000
[I>1000J1.0413.oJo2.612.3172.212.1102.0J1l.94Ji.asl1.a311.7l91.7s11.n11.5191.5171.6411.1612.6l11.s9l1.s7l1.s4l1.s211.sol1.4a11.4161.4121.4l0u7 lus lu2 luo l1.2al1.2sJ1.1711.111.oa~I> 1000
1
1~~/
j'j'l3l4l5l5l7l5l5FFFFFFFFFFFFFFFFFFFFFFF
11001200isoo110001>1000

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t Table
cum. prob
one-tail
two-tails
df
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
40
60
80
100
1000
z
f.50
0.50
1.00
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0%
t .75
0.25
0.50
1.000
0.816
0.765
0.741
0.727
0.718
0.711
0.706
0.703
0.700
0.697
0.695
0.694
0.692
0.691
0.690
0.689
0.688
0.688
0.687
0.686
0.686
0.685
0.685
0.684
0.684
0.684
0.683
0.683
0.683
0.681
0.679
0.678
0.677
0.675
0.674
50%
t .80
0.20
0.40
t .85
0.15
0.30
1.376
1.061
0.978
0.941
0.920
o.i:fo6
0.896
0.889
0.883
0.879
0.876
0.873
0.870
0.868
0.866
0.865
0.863
0.862
0.861
0.860
0.859
0.858
0.858
0.857
0.856
0.856
0.855
0.855
0.854
0.854
0.851
0.848
0.846
0.845
0.842
0.842
60%
1.963
1.386
1.250
1.190
1.156
1.134
1.119
1.108
1.100
1.093
1.088
1.083
1.079
1.076
1.074
1.071
1.069
1.067
1.066
1.064
1.063
1.061
1.060
1.059
1.058
1.058
1.057
1.056
1.055
1.055
1.050
1.045
1.043
1.042
1.037
1.036
70%
t .90
0.10
0.20
t .95
0.05
0.10
t .975
0.025
0.05
3.078
1.886
1.638
1.533
1.476
1.440
1.415
1.397
1.383
1.372
1.363
1.356
1.350
1.345
1.341
1.337
1.333
1.330
1.328
1.325
1.323
1.321
1.319
1.318
1.316
1.315
1.314
1.313
1.311
1.310
1.303
1.296
1.292
1.290
1.282
6.314
2.920
2.353
2.132
2.015
1.943
1.895
1.860
1.833
1'.812
1.796
1.782
1.771
1.761
1.753
1.746
1.740
1.734
1.729
1.725
1.721
1.717
1.714
1.711
1.708
1.706
1.703
1.701
1.699
1.697
1.684
1.671
1.664
1.660
1.646
12.71
4.303
3.182
2.776
2.571
2.447
2.365
2.306
.2.262
2.228
2.201
2.179
2.160
2.145
2.131
2.120
2.110
2.101
2.093
2.086
2.080
2.074
2.069
2.064
2.060
2.056
2.052
2.048
2.045
2.042
2.021
2.000
1.990
1.984
1.962
1.282 1.645 1.960
80% 90% 95%
Confidence Level
t .99
0.01
0.02
t.995
0.005
0.01
t .999
0.001
0.002
t .9995
o.ooosl
0.001
31.82
6.965
4.541
3.747
3.365
3.143
2.998
2.896
2.821
2.764
2.718
2.681
2.650
2.624
2.602
2.583
2.567
2.552
2.539
2.528
2.518
2.508
2.500
2.492
2.485
2.479
2.473
2.467
2.462
2.457
2.423
2.390
2.374
2.364
2.330
2.326
98%
63.66
9.925
5.841
4.604
4.032
3.707
3.499
3.355
3.250
3.169
3.106
3.055
3.012
2.977
2.947
2.921
2.898
2.878
2.861
2.845
2.831
2.819
2.807
2.797
2.787
2.779
2.771
2.763
2.756
2.750
2.704
2.660
2.639
2.626
2.581
2.576
99%
318.31
22.327
10.215
7.173
5.893
5.208
4.785
4.501
4.297
4.144
4.025
3.930
3.852
3.787
3.733
3.686
3.646
3.610
3.579
3.552
3.527
3.505
3.485
3.467
3.450
'3.435
3.421
3.408
3.396
3.385
3.307
3.232
3.195
3.174
3.098
3.090
99.8%
636.62
31.599
12.924
8.610
6.869
5.959
5.4081
5.041
4.781
4.587
4.437
4.318
4.221
4.140
4.073
4.015
3.965
3.922
3.883
3.850
3.819
3.792
3.768
3.745
3.725
3.707
3.690
3.674'
3.659
3.646
3.551
3.460
3.416
3.390
3.300
3.291
99.9%
t-table.xls 7/14/2007