two population regressions
18.1 given:
For sample 1 : n = 28, ∑x2 = 142.35, ∑xy = 69.47, ∑y2 = 108.77, = 14.7 = 32.0.
For sample 2 : n = 30, ∑x2 = 181.32, ∑xy = 97.40, ∑y2 = 153.59, = 15.8 = 27.4.
a) Test H0: β1 = β2 vs. H0: β1 ≠ β2.
b) If H0 in part (a ) is not rejected, test H0 the elevations the two population regressions are the same, vs. HA: the two elevation are not the same.
c)
sample 1 sample 2
n = 28 n = 30
∑x2 = 142.35 ∑x2 = 181.32
∑xy = 69.47 ∑xy = 97.40
∑y2 = 108.77 ∑y2 = 153.59
= 14.7 = 15.8
= 32.0 = 27.4
b= = 0.4880 b= =0.5371
residual SS =108.77 – residual SS =153.59 –
=74.8670 = 101.2694
residual DF = 28-2 = 26 residual DF = 30-2 = 28
(s2y.x)p = = 3.2617
Sb1-b2 = = 0.20224
T= =
rejectH0if ≥ tα but not reject H0 because < = 2.015
I. Sum of squares of x for common regression Ac = (∑x2)1 + (∑x2)2
142.35 +181.32 = 323.67
II. Sum of crossproducts for common regression: Bc = (∑xy)1+(∑xy)2
69.47 +97.40 = 166.87
III. Sum of squares of y for common regression: Cc = (∑y2)1+(∑y2)2
108.77 +153.59 =262.36
IV. Residual ss for common regression: SSc = Cc-
=176.32917
V. Residual DF for common regression: DF =n1+n2 -3
DF =28+30 -3 =55
VI. Residual MS for common regression:( s2y.x) =
=3.20598
VII. bc for common regression: = = 0.515556
VIII. then, the appropriate test statistic is: t =
t = = =10.6971
reject H0 because t =10.6971>
comparing two elevation for the tow lines in example 18.8 and fig 18.8 in 2 sample:
Sample1: sample 2:
SSx = 1470.8712 SSx =2272.4750
Scpxy = 4363.1624 Scpxy =4928.8100
SSy = 13299.5296 SSy =10964.0947
n = 26 n = 30
b = 2.97 b = 2.17
SSr = 356.7317 SSr = 273.9142
a 1= 10.57 a 2 = 24.91
= 10.57 + 2.97 xi = 24.91 + 2.17 xi
= 22.93 =18.95
= + & = +
=10.57+ =66.406 & =24.91+ = 65.706
= =1.59264 =
= = 1.0114
t = =0.6921
do not reject H0 because tc = 0.6921 < = 2.007 & = 2.68
متولد 1362 کرمانشاه و مقیم تهران هستم تحصیلات مقاطع کاردانی، کارشناسی و کارشناسی ارشد را به ترتیب در دانشگاههای لرستان(تکنولوژی تولیدات دامی)، شهید با هنر کرمان(مهندسی تولیدات دامی)و کردستان(ژنتیک و اصلاح نژاد دام)گذرانده ام.