Mon Feb 24 07:57:56 2020 

leastsquares_test
  R version 3.4.4 (2018-03-15) 
  leastsquares solves a linear system using the normal equations.

The matrix A:

      [,1] [,2] [,3]
 [1,]    1  8.3   70
 [2,]    1  8.6   65
 [3,]    1  8.8   63
 [4,]    1 10.5   72
 [5,]    1 10.7   81
 [6,]    1 10.8   83
 [7,]    1 11.0   66
 [8,]    1 11.0   75
 [9,]    1 11.1   80
[10,]    1 11.2   75
[11,]    1 11.3   79
[12,]    1 11.4   76
[13,]    1 11.4   76
[14,]    1 11.7   69
[15,]    1 12.0   75
[16,]    1 12.9   74
[17,]    1 12.9   85
[18,]    1 13.3   86
[19,]    1 13.7   71
[20,]    1 13.8   64
[21,]    1 14.0   78
[22,]    1 14.2   80
[23,]    1 14.5   74
[24,]    1 16.0   72
[25,]    1 16.3   77
[26,]    1 17.3   81
[27,]    1 17.5   82
[28,]    1 17.9   80
[29,]    1 18.0   80
[30,]    1 18.0   80
[31,]    1 20.6   87

The right hand side b:

 [1] 10.3 10.3 10.2 16.4 18.8 19.7 15.6 18.2 22.6 19.9 24.2 21.0 21.4 21.3 19.1
[16] 22.2 33.8 27.4 25.7 24.9 34.5 31.7 36.3 38.3 42.6 55.4 55.7 58.3 51.5 51.0
[31] 77.0

The least squares solution x:

[1] -57.9876589   4.7081605   0.3392512

leastsquares_test
  Normal end of execution.
Mon Feb 24 07:57:57 2020