Usando proporciones, se encuentra que 400 africanos han participado.
En total, hay x participantes.
de los corredores son europeos, o sea:
Los americanos son la dècime parte de los europeos, o sea:
Los africanos son la quinta parte de los americanos, o sea:
En la carrera han inscritos 24 000 participantes, o sea, . Por eso, la cantidad de africanos es:
Para obtener más información sobre las proporciones, puedes visitar a brainly.com/question/24615636
Using the z-distribution, it is found that the 95% confidence interval is (0.46, 0.526), and it does not provide strong evidence against that belief.
<h3>What is a confidence interval of proportions?</h3>A confidence interval of proportions is given by:
In which:
In this problem, we have a 95% confidence level, hence, z is the value of Z that has a p-value of
, so the critical value is z = 1.96.
We have that a random sample of 864 births in a state included 426 boys, hence the parameters are given by:
Then, the bounds of the interval are given by:
The 95% confidence interval estimate of the proportion of boys in all births is (0.46, 0.526). Since the interval contains 0.506, it does not provide strong evidence against that belief.
More can be learned about the z-distribution at brainly.com/question/25890103