Mask mandate or not. Are masks even helpful?

I am a believer in science, and as such I want to get as much information as possible before making a judgement regarding masks. So I took the official statistics of coronavirus 19 cases and deaths for the 50 states and some territories for the seven day period between March 22 thru March 28, divided them up into states with mask mandates and states with no current mask mandates, totaled them up, and this is what I found:

The total death rate for states with mask mandates: 1.46%. The total death rate for states with no mask mandates: 2.02%. This seems to indicate that wearing masks reduce deaths by 28%.

The counter argument to this is that the State of California, one of the most restrictive state in the union had a death rate of 7.63%, while South Dakota, a state that never had a lockdown, nor a mask mandate had a death rate of 0.5%. This seems to indicate that not having a mask mandate is 15 times better.

Obviously the truth is somewhere in between, wearing masks may or may not improve the situation.

These are the U.S. states and territories with mask mandates:

State                          Cases    Deaths Death rate

                                      Last seven days

California                  2635     201   7.63%

Kentucky                     600       29   4.83%

Arkansas                      182        8   4.40%

Louisiana                     349       14   4.01%           

Alabama                       419      16   3.82%

Nevada                          281       9   3.20%

New Mexico                191       5   2.62%

Kansas                          188        4   2.13%

Massachusetts           2123       36   1.70%               

Utah                             424        7    1.65%

North Carolina          1819       26|   1.43%

Indiana                         848       11   1.30%

Ohio                            1703       22   1.29%

New York                   8171     102   1.25%             

 Hawaii                           91         1    1.10%

Maryland                   1146       12|   1.05%

Illinois                        2281      23    1.01%

West Virginia              412         4   0.97%

New Hampshire          339         3    0.88%

Virginia                     1506       12|   0.80%

Delaware                      253        2    0.79%

Pennsylvania             4019       30   0.75%

District of Columbia    135       1     0.74%

New Jersey                4462       31   0.69%

Wisconsin                    468         3   0.64%

Vermont                       167        1   0.60%

Washington               1022         6   0.59%

Oregon                        351          2   0.57%

Colorado                    1132        6    0.53%

Maine                           197        1   0.51%|

Michigan                    4662      21   0.45%

Minnesota                  1405         6   0.43%    

Connecticut               1217         5    0.41%

 American Samoa           0         0   0.00%

Total 45201 660 1.46%

These are the states and territories without mask mandates:

State                   Cases/day  Deaths Death rate

                                      Last seven days

Georgia                       1434     58   4.04%

Arizona                        547      20   3.66%

Texas                           3359   100   2.98%

Montana                        152       4   2.63%

Oklahoma                      343      9   2.62%

Mississippi                   252        6   2.38%

Nebraska                       315       5   1.59%

Florida                         5137     69   1.34%

South Carolina           1108    14   1.26%

Missouri                       699        8   1.14%

Iowa                              607       8   1.32%

Alaska                          102        1   0.98%

Tennessee                  1149      9   0.78%     

North Dakota               134       1   0.75%

Idaho                             287       2   0.70%

Wyoming                        62      0.4 0.62%

South Dakota                200       1   0.50%   

Total 15877 320 2.02%