my @data    = ('70.1', '75.3','76.5', '87.4');
my @numbers = ('0.001','0.34','0.456','0.521');

##</code><code>##

my %look_up;
@look_up{@data} = @numbers;

##</code><code>##

print $look_up{76.5}, "\n";   # prints: 0.456