In the population of young children eligible to participate in a study of whether or not their calcium intake is adequate, 52% are 5 to 10 years of age and 48% are 11 to 13 years of age. For those who are 5 to 10 years of age, 17% have inadequate calcium intake. For those who are 11 to 13 years of age, 54% have inadequate calcium intake. Use Bayes's rule to find the probability that a child from this population who has inadequate intake is 11 to 13 years old.

Respuesta :

Answer:

0.7457 = 74.57% probability that a child from this population who has inadequate intake is 11 to 13 years old.

Step-by-step explanation:

Bayes Theorem:

Two events, A and B.

[tex]P(B|A) = \frac{P(B)*P(A|B)}{P(A)}[/tex]

In which P(B|A) is the probability of B happening when A has happened and P(A|B) is the probability of A happening when B has happened.

In this question:

Event A: Inadequate intake

Event B: Is 11 to 13 years old.

48% are 11 to 13 years of age.

This means that [tex]P(B) = 0.48[/tex]

For those who are 11 to 13 years of age, 54% have inadequate calcium intake.

This means that [tex]P(A|B) = 0.54[/tex]

Probability of inadequate calcium intake:

0.17 of 0.52(5 to 10 years old)

0.54 of 0.48(11 to 13 years old). So

[tex]P(A) = 0.17*0.52 + 0.54*0.48 = 0.3476[/tex]

Find the probability that a child from this population who has inadequate intake is 11 to 13 years old.

[tex]P(B|A) = \frac{P(B)*P(A|B)}{P(A)} = \frac{0.48*0.54}{0.3476} = 0.7457[/tex]

0.7457 = 74.57% probability that a child from this population who has inadequate intake is 11 to 13 years old.