Answer:
α = 0.01 ; 2 - tailed
χ² = 16.998
Pvalue = 0.1497
Fail to reject H0
Step-by-step explanation:
Given the data above :
Number of People Making Contribution
Ethnic Group $1-50 $51-100 $101-150 $151-200 Over $200 Row Total
A 77 63 54 39 18 251
B 90 48 76 26 24 264
C 73 67 59 37 30 266
D 108 82 70 50 30 340
Column Total 348 260 259 152 102 1121
1.) The level of significance, α/2 = 0.01/2
2.)
The hypothesis :
H0 : Contribution and Ethnic group are independent
H1 : Contribution and Ethnic group are not independent
The Chisquare statistic :
χ² = (Observed - Expected)²/ Expected
The expected value for each cell is calculated thus :
(Row total * column total) / sum total
The expected values :
77.9197 58.2159 57.992 34.0339 22.8385
81.9554 61.231 60.9955 35.7966 24.0214
82.5763 61.6949 61.4576 36.0678 24.2034
105.549 78.8582 78.5549 46.1017 30.9367
Using the χ² formula above ;
χ² values for each cell are :
0.010855 0.393154 0.274794 0.724635 1.02509
0.789645 2.85902 3.69099 2.68108 0.0000191
1.11055 0.456179 0.098278 0.0240936 1.38826
0.056933 0.125176 0.93165 0.32963 0.028359
Taking the sum :
0.010855+0.393154+0.274794+0.724635+1.02509+0.789645+2.85902+3.69099+2.68108+0.0000191+1.11055+0.456179+0.098278+0.0240936+1.38826+0.056933+0.125176+0.93165+0.3293+0.028359
χ² = 16.998
To obtain the Pvalue :
df = (Row - 1)(column - 1) = (5-1)*(4-1) = 4 * 3 = 12
Pvalue(16.998 ; 12) = 0.1497
If Pvalue < α ; Reject H0 ;
Since Pvalue > α ; WE fail to reject H0
, where the period is the distance from one peak to the next peak