线性回归X与Y因子设置影响（加分）

我在工作中发现一个问题，请大家帮忙解释一下：
A、B两组数据做线性回归，如果分别把A（客户数据）设为X，B（厂内数据）设为Y，或A设为Y，B设为X，得出的方程差别很大。请各位帮忙看看：
B = 5.649 + 0.9351 A
A = 11.71 + 0.8372 B
我们现在知道A的规格为110，则用两个公式分别得出B=108.51，或117.4
为什么会有这么大的差别？那么是否在做线性回归的时候要特别注意X与Y的设定？请高手指教，谢谢！

数据如下：
A B
67.624 77.47
111.342 102.38
95.713 109.88
73.036 79.87
78.736 80.8
47.477 46.85
81.332 77.84
81.817 90.43
45.59 44.19
62.846 67.41
65.929 64.01
99.319 76.32
87.798 98.57
86.311 89.84
74.769 77.07
117.113 110.48
74.326 83.78
89.954 99.17
46.36 57.53
81.798 62.72
105.527 106.84
99.369 84.61
81.569 79.96
62.045 43.38
96.616 104.53
115.215 122.61
75.284 74.91
60.089 59.5
108.39 124.88
66.627 69.8
57.019 50.65
75.955 84.5
62.082 79.23
62.097 74.08
76.192 87
79.923 77.23
77.891 86.26
71.332 75.66
62.287 56.04
84.589 75.03
81.008 85.89
69.092 75.06
91.73 112.83
73.64 73.2
82.571 74.75
91.999 96.01
89.724 85.54
107.891 103.63
87.57 97.43
81.995 77.29
70.078 51.86
79.611 87.21
81.578 91.21
66.574 61.67
84.935 80.15
97.915 101.42
86.418 96.66
114.712 117.9
75.346 88.71
45.511 50.48
87.909 96.44
86.896 88.89
35.504 38.71
33.891 37.3
55.561 74.81
88.354 81.11
45.305 57.81
61.855 41.02
46.966 52.6
82.021 83.15
102.163 81.99
42.368 37.94
41.835 56.29
70.573 78.34
81.344 89.43
78.449 74.64
57.298 59.53
63.412 75.08
62.973 60.97
47.679 63.21
75.359 70.43
73.036 64.65
63.368 57.83
40.936 42.3
59.229 49
48.239 43.82
109.909 97.42
59.23 42.93
74.536 58.56
120.052 117.53
71.473 74.26
99.336 86.52
73.22 73.28
67.742 56.17