yogi_Compute Percentage For A Specified Amount Based On A Table Of MoreThanAmount And Percentage Table

                                          Google Spreadsheet   Post  #1296
Yogi Anand, D.Eng, P.E.      ANAND Enterprises LLC -- Rochester Hills MI     www.energyefficientbuild.com.   Jul 20, 2013
user post by rcjhutton (http://productforums.google.com/forum/?zx=ypp2d4hsq8dw#!category-topic/docs/spreadsheets/3fFAXnYOvrI)
How to put a set number in a cell depending on the range of another cell
I am not very good with any formulas other then simple adding so hoping someone can help me 


Depending on the number in a cell I want a different number in the cell next to it

if column b2 is more the 650 but less then 1299 I need 10% in column c3
if column b2 is more then 1300 but less then 2249  I need 13% in c3
if column b2 is more then 2250 I need 15% in c3
---
Ok I have kind of sorted it out but for some reason it wont work above 18 ? 

This is the formula I am using and I can't see what's wrong, Any suggestions or am I  missing something?

=if(and(D7>=650;D7<1300);10;if(and(D7>=1300;D7<2250);13;if(and(D7>=2250;D7<3400);15;if(and(D7>=3400;D7<5100);18;if(and(D7>=5100;D7<7500);21;if(D7>=7500;24);"0")))))
The numbers I need are anything below 650 = 0
650 upto 1300 = 10
1300 upto 2250 = 13
2250 upto 3400 = 15

3400 upto 5100 = 18
5100 upto 7500 = 21
anything over 7500 = 24

Hope you can help :)

----------------------------------------------------------------------------------------------------------------------------------------------------