In: Math
Are steers and heifers equally distributed between angus and herefords
| Case | Breed | Sex | |||
| 1 | hereford | Heifer | |||
| 2 | hereford | Heifer | |||
| 3 | hereford | Steer | |||
| 4 | Angus | Steer | |||
| 5 | Angus | Steer | |||
| 6 | hereford | Heifer | |||
| 7 | hereford | Heifer | |||
| 8 | hereford | Heifer | |||
| 9 | hereford | Steer | |||
| 10 | hereford | Steer | |||
| 11 | hereford | Heifer | |||
| 12 | hereford | Heifer | |||
| 13 | Angus | Steer | |||
| 14 | hereford | Heifer | |||
| 15 | Angus | Steer | |||
| 16 | hereford | Heifer | |||
| 17 | Angus | Steer | |||
| 18 | hereford | Heifer | |||
| 19 | Angus | Steer | |||
| 20 | Angus | Steer | |||
| 21 | Angus | Steer | |||
| 22 | Angus | steer | |||
| 23 | Angus | Steer | |||
| 24 | hereford | Steer | |||
| 25 | hereford | Steer | |||
| 26 | hereford | Steer | |||
| 27 | Angus | Steer | |||
| 28 | Angus | Heifer | |||
| 29 | hereford | Steer | |||
| 30 | Angus | Steer | |||
| 31 | hereford | Heifer | |||
| 32 | hereford | Heifer | |||
| 33 | Angus | Steer | |||
| 34 | hereford | Steer | |||
| 35 | hereford | Heifer | |||
| 36 | hereford | Heifer | |||
| 37 | Angus | Steer | |||
| 38 | Angus | Steer | |||
| 39 | Angus | Heifer | |||
| 40 | hereford | Steer | |||
| 41 | hereford | Heifer | |||
| 42 | Angus | Steer | |||
| 43 | Angus | Steer | |||
| 44 | hereford | Steer | |||
| 45 | hereford | Heifer | |||
| 46 | hereford | Heifer | |||
| 47 | hereford | Heifer | |||
| 48 | hereford | Heifer | |||
| 49 | hereford | Heifer | |||
| 50 | hereford | Heifer | |||
| 51 | Angus | Heifer | |||
| 52 | hereford | Steer | |||
| 53 | Angus | Steer | |||
| 54 | Angus | Steer | |||
| 55 | Angus | steer | |||
| 56 | Angus | Heifer | |||
| 57 | hereford | Heifer | |||
| 58 | Angus | steer | |||
| 59 | hereford | Steer | |||
| 60 | hereford | Heifer | |||
| 61 | hereford | Heifer | |||
| 62 | Angus | Heifer | |||
| 63 | hereford | Steer | |||
| 64 | Angus | Steer | |||
| 65 | hereford | Heifer | |||
| 66 | hereford | Heifer | |||
| 67 | hereford | Heifer | |||
| 68 | hereford | Heifer | |||
| 69 | hereford | Heifer | |||
| 70 | Angus | Steer | |||
| 71 | Angus | Steer | |||
| 72 | Angus | Steer | |||
| 73 | Angus | Steer | |||
| 74 | hereford | Heifer | |||
| 75 | hereford | Heifer | |||
| 76 | Angus | Steer | |||
| 77 | hereford | Heifer | |||
| 78 | hereford | Steer | |||
| 79 | Angus | Steer | |||
| 80 | hereford | Heifer | |||
| 81 | Angus | Steer | |||
| 82 | hereford | Steer | |||
| 83 | Angus | Heifer | |||
| 84 | hereford | Steer | |||
| 85 | hereford | Steer | |||
| 86 | hereford | Heifer | |||
| 87 | hereford | Steer | |||
| 88 | hereford | Heifer | |||
| 89 | hereford | Heifer | |||
| 90 | Angus | Steer | |||
| 91 | hereford | Heifer | |||
| 92 | Angus | Steer | |||
| 93 | hereford | Heifer | |||
| 94 | Angus | Heifer | |||
| 95 | Angus | Heifer | |||
| 96 | hereford | Heifer | |||
| 97 | hereford | Steer | |||
| 98 | hereford | Steer | |||
| 99 | Angus | Heifer | |||
| 100 | Angus | Steer | |||
The problem can be modeled using chi square test of independence, where the null hypothesis states that -
steers and heifers are equally distributed between angus and herefords
And, alternate hypothesis states that -
steers and heifers are significantly differently distributed between angus and herefords
Simplifying the table -
| Steer | Heifer | ||
| Angus | 32 | 9 | 41 |
| Hereford | 20 | 39 | 59 |
| 52 | 48 | 100 |
| Steer (observed) | Steer (expected) | chi sq | Heifer (observed) | Heifer (expected) | chi sq | Total | |
| Angus | 32 | 21.32 | 5.35 | 9 | 19.68 | 5.8 | 41 |
| Hereford | 20 | 30.68 | 3.72 | 39 | 28.32 | 4.03 | 59 |
| 52 | 48 | 100 |
Where, expected value = row total * column total / total
and, chi square value = (observed - expected)^2 / expected
combined chi square value = 18.9
Looking at the chi square table for 1 degree of freedom and value of 18.9, the p value is .000014.
(degree of freedom = (row -1) * (column -1)
The result is significant even at 0.0001 significance level.
Hence, we reject our null hypothesis.
steers and heifers are significantly differently distributed between angus and herefords