High School

A sociologist claims that [tex]$25 \%$[/tex] of adults would describe themselves as organized. A random sample of 100 adults reveals 42 who describe themselves as organized. Do these data provide convincing evidence that greater than [tex]$25 \%$[/tex] of adults would describe themselves as organized? Use [tex]\alpha=0.01[/tex].

Are the conditions for inference met?

1. **Random:** We have a random sample of
[tex]\square[/tex]

2. **10% Condition:** 100 adults [tex] \ < \ 10 \%[/tex] of
[tex]\square[/tex]

3. **Large Counts:**
[tex]n p_0 = \square[/tex]
[tex]n\left(1-p_0\right) = \square[/tex]

These values are both at least [tex]\square[/tex].

Answer :

To determine if the conditions for inference are met, let's evaluate each of the conditions required for conducting a hypothesis test.

1. Random Condition: The sample needs to be random. In this scenario, we are given a random sample of 100 adults. This condition is satisfied as we have a random sample of 100.

2. 10% Condition: The sample size should be less than 10% of the population to ensure independence of the sample. Since 100 adults is less than 10% of a much larger adult population, this condition is met.

3. Large Counts Condition: This condition checks whether the sample size is large enough for the normal approximation to the binomial distribution to be appropriate. It requires both [tex]\(n \times p_0\)[/tex] and [tex]\(n \times (1 - p_0)\)[/tex] to be at least 10, where [tex]\(n\)[/tex] is the sample size and [tex]\(p_0\)[/tex] is the hypothesized population proportion.

- Calculate [tex]\(n \times p_0\)[/tex]:
[tex]\[
n \times p_0 = 100 \times 0.25 = 25.0
\][/tex]
- Calculate [tex]\(n \times (1 - p_0)\)[/tex]:
[tex]\[
n \times (1 - p_0) = 100 \times (1 - 0.25) = 100 \times 0.75 = 75.0
\][/tex]

Both calculations (25.0 and 75.0) are greater than or equal to 10, so the Large Counts condition is satisfied.

In conclusion, all the conditions for inference are met: the sample is random, the sample size is less than 10% of the population, and the required counts for the normal approximation are sufficient. Therefore, you can proceed with the hypothesis test to determine if more than 25% of adults would describe themselves as organized.