@jeonkook,
Setting floating values in minimum and maximum of y-axis seems to be working fine. Please take a look at this JSFiddle for the same.
axisY: {
maximum: 7.4,
minimum: 7.2
}
If you are still facing the issue, kindly create JSFiddle reproducing the issue you are facing and share it with us so that we can understand your scenario better and help you out.
—-
Manoj Mohan
Team CanvasJS