the given degree of confidence and sample data to construct a confidence interval for the population proportion p. Round to three decimal digits needed. Of 147 randomly selected adults, 34 were found to have high blood pressure. Construct a 95% confidence interval for the true percentage of all Its that have high blood pressure.

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### Constructing a 95% Confidence Interval for Population Proportion

In this example, we are given the following data:
- A sample of 147 randomly selected adults.
- Out of these, 34 were found to have high blood pressure.

The task is to construct a 95% confidence interval for the true percentage of all adults that have high blood pressure. The confidence interval will be rounded to three decimal places as required.

#### Step-by-Step Solution:

1. **Sample Proportion (p̂):**
   \[ \hat{p} = \frac{x}{n} = \frac{34}{147} \]
   Calculating this gives:
   \[ \hat{p} \approx 0.231 (rounded to three decimal places) \]

2. **Standard Error (SE):**
   \[ SE = \sqrt{\frac{\hat{p}(1 - \hat{p})}{n}} \]
   Plugging in the numbers:
   \[ SE = \sqrt{\frac{0.231 \times (1 - 0.231)}{147}} \approx 0.035 (rounded to three decimal places) \]

3. **Critical Value (Z*) for a 95% Confidence Interval:**
   The critical value for a 95% confidence level is approximately 1.96.

4. **Confidence Interval Calculation:**
   \[ \text{Margin of Error (ME)} = Z^* \times SE = 1.96 \times 0.035 \approx 0.069 \]
   Therefore, the 95% confidence interval is:
   \[ \hat{p} \pm \text{ME} \]
   \[ 0.231 \pm 0.069 \]

5. **Result:**
   \[ \text{Confidence Interval} = (0.162, 0.300) \]

So, the 95% confidence interval for the true percentage of all adults that have high blood pressure is approximately (0.162, 0.300). This means we are 95% confident that the true proportion of adults with high blood pressure lies between 16.2% and 30.0%.
Transcribed Image Text:### Constructing a 95% Confidence Interval for Population Proportion In this example, we are given the following data: - A sample of 147 randomly selected adults. - Out of these, 34 were found to have high blood pressure. The task is to construct a 95% confidence interval for the true percentage of all adults that have high blood pressure. The confidence interval will be rounded to three decimal places as required. #### Step-by-Step Solution: 1. **Sample Proportion (p̂):** \[ \hat{p} = \frac{x}{n} = \frac{34}{147} \] Calculating this gives: \[ \hat{p} \approx 0.231 (rounded to three decimal places) \] 2. **Standard Error (SE):** \[ SE = \sqrt{\frac{\hat{p}(1 - \hat{p})}{n}} \] Plugging in the numbers: \[ SE = \sqrt{\frac{0.231 \times (1 - 0.231)}{147}} \approx 0.035 (rounded to three decimal places) \] 3. **Critical Value (Z*) for a 95% Confidence Interval:** The critical value for a 95% confidence level is approximately 1.96. 4. **Confidence Interval Calculation:** \[ \text{Margin of Error (ME)} = Z^* \times SE = 1.96 \times 0.035 \approx 0.069 \] Therefore, the 95% confidence interval is: \[ \hat{p} \pm \text{ME} \] \[ 0.231 \pm 0.069 \] 5. **Result:** \[ \text{Confidence Interval} = (0.162, 0.300) \] So, the 95% confidence interval for the true percentage of all adults that have high blood pressure is approximately (0.162, 0.300). This means we are 95% confident that the true proportion of adults with high blood pressure lies between 16.2% and 30.0%.
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