A study is carried out to determine risk factors for kyphosis, which is severe

forward flexion of the spine following corrective spinal surgery. The age in

months at the time of the operation for the 18 subjects for whom kyphosis was

present were 12, 15, 42, 52, 59, 73, 82, 91, 96, 105, 114, 120, 121, 128, 130, 139,

139, 157 and for the 22 subjects for whom kyphosis was absent were 1, 1, 2, 8,

11, 18, 22, 31, 37, 61, 72, 81, 97, 112, 118, 127, 131, 140, 151, 159, 177, 206.

Fit a logistic regression model using age as a predictor of whether kyphosis is

present. Test whether age has a significant effect