Math Problem Statement

In a random sample of 355 patients of a primary care doctor, it was found that 103 have high blood pressure and 252 do not. A 98% confidence interval was constructed to estimate the proportion of all patients that have high blood pressure. This confidence interval came out to be (.2341, .3462). What is a point estimate of the proportion of all patients that have high blood pressure?

Answer = Round to 4 decimal places.

(b) What is the margin of error?

Answer = Round to 4 decimal places.

Solution

Let's solve both parts of the question systematically.

(a) Point Estimate of the Proportion

The point estimate is the sample proportion, p^\hat{p}, which is calculated by dividing the number of patients with high blood pressure by the total number of patients in the sample.

p^=Number of patients with high blood pressureTotal number of patients=103355\hat{p} = \frac{\text{Number of patients with high blood pressure}}{\text{Total number of patients}} = \frac{103}{355}

p^0.2901\hat{p} \approx 0.2901

So, the point estimate of the proportion of patients with high blood pressure is 0.2901 (rounded to 4 decimal places).

(b) Margin of Error

The margin of error (ME) is the difference between the upper bound of the confidence interval and the point estimate, or equivalently, the difference between the point estimate and the lower bound.

Margin of Error=Upper Boundp^=0.34620.2901=0.0561\text{Margin of Error} = \text{Upper Bound} - \hat{p} = 0.3462 - 0.2901 = 0.0561

Thus, the margin of error is 0.0561 (rounded to 4 decimal places).

Final Answers:

  • Point estimate = 0.2901
  • Margin of error = 0.0561

Do you want more details on how to compute confidence intervals or any other clarifications?

Here are 5 related questions to expand your understanding:

  1. How would you calculate the sample standard deviation in this context?
  2. What does a 98% confidence interval mean in terms of interpretation?
  3. How would the confidence interval change if the confidence level were reduced to 90%?
  4. What formula is used to construct a confidence interval for a proportion?
  5. How can we check if a larger sample size is needed for a more precise estimate?

Tip: Increasing the sample size decreases the margin of error, leading to more precise estimates of population parameters.

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Math Problem Analysis

Mathematical Concepts

Statistics
Confidence Interval
Proportion
Margin of Error

Formulas

Point Estimate: p̂ = x / n
Margin of Error: ME = Upper Bound - Point Estimate

Theorems

Confidence Interval for Proportion

Suitable Grade Level

Undergraduate or Advanced High School (Grades 11-12)