Do you see anything wrong with my maths?

[Anonymous]

I read this online

About 1 in 400 male and 1 in 650 female live births demonstrate some form of sex chromosome abnormality.

There is 8 billion people worldwide.

8 billion/400 = twenty million

8 billion / 650 = 12,307,692 million

20 million + 12,307,692 million = 32,307,692 million

32,307,692 / 8 billion x 100 = 0.40384615 percentage

Would this mean less than 1 percentage of the world human population has a chromosome abnormality?

[GuyAnswersGirls123]

The percentage is already given in the original figure (1/400=0.25% of males, 1/650=~0.15% of females) assuming it extrapolates.

If you want to try to extrapolate it to estimate the total number of both males and females in the total world's population though, you made an error dividing 8 billion by 400 and then by 650 and summing the results.

You have to split that 8 billion down into males and females. For simplicity, suppose there are 4 billion males and 4 billion females. Then the total estimated number would be:

(4 billion / 400) + (4 billion / 650) = 16,153,846 (half your number)

And yes, considerably less than 1% if the figure extrapolates, but that's already given by the original statement that only 1/400 male births and only 1/650 female births demonstrate sex chromosomal abnormalities.

[DreamCrescent]

good job. that was my feedback, too

[GuyAnswersGirls123]

You can estimate it quickly just from the original figure. Depending on the ratio of male vs. female live births, the percentage of living people on the planet (assuming the figure extrapolates) will be somewhere between 1/400 and 1/650, so somewhere between ~0.15% and 0.25%.

I emphasize "assuming it extrapolates" since even if the percentage of live births is reasonably accurate, there are other factors that could skew things when you try to determine the ratio by taking samples of the world's total population. For example, even among live births that survive onwards, if offspring with sex chromosomal abnormalities have a nontrivially shorter life expectancy than those without, that's going to be a biasing factor when you simply take samples in time of the world's total population, as there will typically be more members represented in that sample with a longer life expectancy when we don't start to exclude elderly people, for example, from that sample.

[GuyAnswersGirls123]

@DreamCrescent Cheers! 🍻

[DreamCrescent]

💕💕

[joehypo1]

I was born with hypospadias and they said that it was 1 in 300 which is bull shit i have never met another person with it in my entire life

[FreyaRed]

you have to divide those 8 billion with 2 because it contains male and female population.

8 000 000 000 / 2 / 400 = 10 000 000 in male world population
8 000 000 000 / 2 / 650 = 6 153 846 in female world population

[Kelley1]

It is less than 1% but your math is off. They way you are calculating it should be 4 billion in stead ot 8 billion since there are only 4 billion males and 4 billion females.

[Phoenix98]

I think it’s pretty close because just for the US population if I’m remembering right it was like 0.3%

[shortster]

First off half of 8 billion is male or female. Secondly, chromosomal anomalies often lead to miscarriages; most that make it past birth are sterile.

[HouseMoat]

Mutations are hard to come by, that's why you hardly ever see redheaded people