Answer:
Explanation:
Look at the population statistics. Let's say it contains:
- data on the age groups available in the population
- data on the probability that a child in the population has inadequate calcium intake OR data that a child in the population does not have the deficiency. If you're given one of these, the other can be gotten by subtracting the probability value given from 1.
So let's say there are children from ages 5 to 15 in this population and the probability that a child in this population has the deficiency is 0.23 (not all the children in this population of 5-15 year olds may have the deficiency) while the probability that a child in this population does not have the deficiency is [1-0.23] = 0.77
So if you pick a child randomly from the population and he has this deficiency, what is the probability that he or she is between 11 and 13 years old?
From ages 5-15, ages 11, 12 and 13 are 3 ages. The total number of ages is 11 ages.
3÷11 = 0.2727
This is the probability that a child picked or selected at random from the population is 11, 12, or 13 years old.
0.2727 × 0.23 = 0.0627
This is the probability that a child picked at random is BOTH within the age bracket 11 to 13 AND has the deficiency!
Apply this.