I guess they’re saying if you excluded the top 10% and only considered the 90th percentile and below (most regular people), the median of that value would be living on less than $40k a year. Personally I wouldn’t be surprised if it was a lot lower and their “60% live on less than $40k” is understating the issue. That’s a household with two parents earning minimum wage or doing give work which is an incredibly common low income setup.