Answer:
The percentage of the variability in plant weight is NOT explained by height is  
        %
%
Step-by-step explanation:
From the question we are told that 
       The correlation between height and weight is  
Generally the R-Squared  between height and weight is mathematically represented as 
         
substituting values 
          
          
This R-Squared tells us the percentage of plant weight is accounted by height 
 and from the calculation we see that it is  56.3%
Now the percentage of plant weight that is not accounted by height is 
           
            %
%