Based on the data collected by the National Centre for health Statistics and made available to the public in the Sample Adult database, it was found that the percentage of adults who have at some point in their life been told that they have hypertension was 24 percent. Suppose that a random sample of 20 adults is taken. What is the expected number of the adults that have not been told that they have hypertension?
I believe this is a binnomal random variable. What I don't understand is how do you calculate a variable? I can get the probabilty when given a variabl (eg. P(X<3)). Not the other way round.
Please help.
You are making a mountain out of a mole hill I think:
.24 * 20 is the number that have been told
20 - .24*20 = number that have not been told
To calculate the expected number of adults who have not been told they have hypertension, we first need to understand the concept of a binomial random variable.
In this case, the variable of interest is whether or not an adult has been told they have hypertension. Since each adult can either fall into the "told they have hypertension" category or the "not told they have hypertension" category, it follows a binomial distribution.
Now, let's calculate the expected number of adults who have not been told they have hypertension. We know that the percentage of adults who have been told they have hypertension is 24%. Therefore, the percentage of adults who have not been told they have hypertension is 100% - 24% = 76%.
To find the expected number, we multiply the percentage of adults who have not been told they have hypertension by the total sample size. In this case, the sample size is 20.
Expected number of adults not told they have hypertension = (Percentage of adults not told they have hypertension) * (Sample size)
Expected number = 0.76 * 20
Expected number = 15.2
Therefore, the expected number of adults who have not been told they have hypertension is 15.2.