That is for those that get infected, not the whole population.
You can have your crayons back, now.
You doubled-down and lost again.
The 70+ group does NOT include those 80 and older, whose survival rate is around 82% last I checked. Taken as a whole, the doc’s numbers are likely pretty accurate, even measured across the population as a whole.
If 60% of people 70-79 become infected and 5.4% die, that’s 3.24% of that group. And if 60% of people 80 and older become infected and 18% die, that’s 10.8% of that group. That averages out to 7%. Assuming that are more people age 70-79 than 80-110, the total percentage skews down closer to... (wait for it) 5%.
Or 1 in 20.