For the record, I would not have predicted this. If you look at the CDC life tables, and scroll to page 35 (“Table 14. Life table for non-Hispanic white males: United States, 2010”), then scroll a little further down, you’ll see that, of 100,000 non-Hispanic white males born in the United States, 53,857 will survive to their 79th birthday. Justice Scalia would have been 84.9 years old on Inauguration Day, 2021. Of those 53,857 who make it to their 79th birthday, 38,053 are still alive on their 84th birthdays; 34,567 are alive on their 85th. So if you count 84.9 as “84 years old”, he had a 29% chance of dying before the 2021 inauguration. If you count it as 85, the number rises to 35%. If you interpolate between those two probabilities, you get (duh) a number between 29% and 35%. So I would not have bet money on his death.
The probability of one or more Justices’ dying, independently, between now and Inauguration Day 2021 was in the 85+% range. The expected number of Justices who’d die was around 1.7. I’ll have to re-run the numbers now with only 8 Justices.