Larry's shoulder height is 20% less than 5 feet, or 0.2*5 =<<20*.01*5=1>>1 foot less than 5 feet.
One foot less than 5 feet is 5-1=<<5-1=4>>4 feet.
If Barry stands on Larry's shoulders, they can reach 4+5=<<4+5=9>>9 feet.
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