Excel IF Formulae , working with Number ranges

I have a formulae I am trying to work on but it seems not to be working. I am working with number ranges

3.5 - 4 None

3.4- 3 Low

2.9 - 2 Medium

1.9 - 0 High

I have IF formulae which is suppose to give me a result based on the ranges. I cant seem to make it work

=IF(D13>3.5,"None",IF(D13<3.4,"Low",IF(D13<2.9,"Med",IF(D13<1.9,"High"))))