Math Problem Statement

A simple random sample of n=17 is drawn from a population that is normally distributed with  . The sample mean is found to be  .  Construct a 98% confidence interval for the population mean.   Confidence interval:  (,) 

Solution

To construct a 98% confidence interval for the population mean from a simple random sample, we typically use the formula for the confidence interval when the population is normally distributed and the sample size is small:

Confidence Interval=xˉ±tα/2×sn\text{Confidence Interval} = \bar{x} \pm t_{\alpha/2} \times \frac{s}{\sqrt{n}}

Where:

  • xˉ\bar{x} is the sample mean.
  • tα/2t_{\alpha/2} is the critical value from the tt-distribution for the desired confidence level.
  • ss is the sample standard deviation.
  • nn is the sample size.

Steps:

  1. Identify the sample mean xˉ\bar{x}, sample size nn, and sample standard deviation ss. (You should provide these values for calculation.)
  2. Find the critical value tα/2t_{\alpha/2} for a 98% confidence level with n1n - 1 degrees of freedom.
    • For a 98% confidence level, α=10.98=0.02\alpha = 1 - 0.98 = 0.02, so α/2=0.01\alpha/2 = 0.01.
    • Using n1=16n - 1 = 16 degrees of freedom, we find tα/2t_{\alpha/2} from the tt-distribution table or a calculator.
  3. Plug values into the formula to calculate the margin of error and the confidence interval.

Could you provide the sample mean and standard deviation for the calculation, or would you like me to demonstrate with assumed values?

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Math Problem Analysis

Mathematical Concepts

Statistics
Confidence Intervals
t-Distribution

Formulas

Confidence Interval = x̄ ± t_(α/2) * (s / √n)

Theorems

Central Limit Theorem
t-Distribution

Suitable Grade Level

Grades 10-12