High School

According to a recent study, [tex]15\%[/tex] of adults who take a certain medication experience side effects. To further investigate this finding, a researcher selects a separate random sample of 150 adults, of which 32 experience side effects. The researcher would like to determine if there is convincing statistical evidence that the true proportion of adults who would experience side effects from this medication is greater than 0.15, using a significance level of [tex]\alpha=0.05[/tex].

Complete the "State" and "Plan" steps. Which statements are true? Check all that apply.

- [tex]H_0: p=0.15[/tex]
- [tex]H_a: p\ \textgreater \ 0.15[/tex]
- The random condition is met.
- The [tex]10\%[/tex] condition is met.
- The large counts condition is met.
- The test is a [tex]z[/tex]-test for one proportion.

Answer :

We begin by stating the hypotheses for the test. The null hypothesis is

[tex]$$
H_0: p = 0.15,
$$[/tex]

which indicates that the proportion of adults experiencing side effects is 15%. Since the research question is whether the true proportion is greater than 0.15, the alternative hypothesis should be

[tex]$$
H_a: p > 0.15.
$$[/tex]

Thus, a provided alternative hypothesis of [tex]$H_a: p < 0.15$[/tex] would be incorrect.

Next, we check the conditions required to perform a [tex]$z$[/tex]-test for one proportion.

1. Random Condition:
The problem states that a random sample of 150 adults is selected. This satisfies the random condition.

2. 10% Condition:
The sample size (150) should be less than 10% of the population. Assuming the overall population of adults is large, this condition is met.

3. Large Counts Condition:
We verify that the expected counts of successes and failures are at least 10. With [tex]$p = 0.15$[/tex] and [tex]$n = 150$[/tex]:
[tex]$$
np = 150 \times 0.15 = 22.5,
$$[/tex]
and
[tex]$$
n(1-p) = 150 \times 0.85 = 127.5.
$$[/tex]
Since both values are greater than 10, the large counts condition is satisfied.

4. Type of Test:
Given that all conditions are met and the data deals with one proportion, the appropriate test is a [tex]$z$[/tex]-test for one proportion.

In summary, the true statements are:

1. [tex]$H_0: p = 0.15$[/tex]
2. (Not true) [tex]$H_a: p < 0.15$[/tex] is incorrect; the correct alternative should be [tex]$p > 0.15$[/tex].
3. The random condition is met.
4. The 10% condition is met.
5. The large counts condition is met.
6. The test is a [tex]$z$[/tex]-test for one proportion.

Therefore, the correct statements are numbers 1, 3, 4, 5, and 6.