statistik
Post on 14-Feb-2016
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QUESTION
1. Sales, in hundreds of Ringgit Malaysia of cat food per day for the three shelf heights are as follows :
Shelf heightKnee level Waist level Eye level
77 88 8582 94 8586 93 8778 90 8181 91 80
Is there a significant difference in the average daily sales of this cat food based oh shelf height? Use a 0.01 level a significance.
ANSWER
Knee level Waist level Eye level Totalni 5 5 5 15 = nT i 404 456 418 1278 = T
1) Ʃx2 = 109284 , Ʃx = 1278 , n = 15
2) SST = Ʃ Ʃx2 – T2
n
= 109284 – (1278)2
15
= 398.40
3) SSB = ƩT12 – T2
n1 n
= ⦋T12 + T2
2 + T32 ⦌- T2
n1 n2 n3 n
= 404 2 + 4562 + 4182 – (1278)2
5 5 5 15
= 289.60
4) SSW = SST – SSB
= 398.40 – 289.60
= 108.80
5)
Source Sum of square Df Mean square FBetween 289.60 k – 1 = 3 – 1
= 2 ( v1)= 289.60 2= 144.80
= 144.80 9.07= 15.96
Within 108.80 n – k = 15 – 3 = 12 (v2)
= 108.80 12= 9.07
Total 398.40 n – 1 = 15 – 1 = 14
6) Hypothesis
H0 = µ1 = µ2 = µ3
H1 = atleast one mean are different
7) Significant level, α = 0.01
8) Test statistic
F = MSB
MSW
= 15.96
9) Critical region
Fα , v1 , v2 = F 0.01 , 2, 12 = 6.93 ( From table 9)
10) Decision rule
Reject H0 when F > Fα
Since F = 15.96 > Fα = 6.93, so reject H0
11) Conclusion
Atleast one mean are different
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