I am looking to create a formula that will give a certain range of numbers a
specific value. For example:

If the number falls between 248 and 258 then give it a value of 4.5
If the number falls between 241 and 247 then give it a value of 4
If the number falls between 230 and 240 then give it a value of 3.5
If the number falls between 220 and 229 then give it a value of 3
If the number falls between 209 and 219 then give it a value of 2.5
If the number falls between 198 and 208 then give it a value of 2

and so forth.

Any assistance with this problem would be greatly appreciated