A multiple regression equation computed from a sample of 88 scores is ŷ=6.3+1.25(x1)+4.63(x2). The estimated standard error of estimate is nine, and the variances of x1 and x2 are 14 and 8 respectively. If the squared correlation between x1 and x2 is .55, then the variance inflation factor is ______.
0.45
2.22
1.82
0.55
