Please explain..

“This increased lifetime translates directly to a lower cost of ownership: extending an EVs life by 3–4 X means an EVs capital cost, per mile, is 1/3 or 1/4 that of a gasoline-powered vehicle”

I can see 4x EV miles => 1/4 EV capital cost per mile. How do you conclude anything about its cost relative to a gasoline-powered vehicle?