43. Kyphosis, or severe forward exion of the spine, may persist despite corrective spinal surgery. A study carried out to determine risk factors for kyphosis reported the following ages (months) for 40 subjects at the time of the operation; the rst 18 subjects did have kyphosis and the remaining 22 did not.

Kyphosis 12 15 42 52 59 73 82 91 96 105 114 120 121 128 130 139 139 157 No kyphosis 1 1 2 8 11 18 22 31 37 61 72 81 97 112 118 127 131 140 151 159 177 206 Use the accompanying MINITAB logistic regression output to decide whether age appears to have a signi cant impact on the presence of kyphosis.

Predictor Coef StDev z P Odds Ratio 95% Lower CI Upper Constant 0.5727 0.6024 0.95 0.342 age 0.004296 0.005849 0.73 0.463 1.00 0.99 1.02