Hina on Nostr: yes, hence on average. Lets say only 1/3 of people initially diagnosed with Down ...

yes, hence on average. Lets say only 1/3 of people initially diagnosed with Down Syndrome actually have it (confirmed by genetic tests, which are expensive). 45 * 1/3 + 100* 2/3 = 81.67, which is a standard deviation below the population average of 100.