Math Problem Statement

A test is made of H₀: μ = 20 versus H₁: μ > 20. A sample of size 39 is drawn. The sample mean and standard deviation are x̄ = 24 and s = 2. Compute the value of the test statistic t. Round your answer to two decimal places.

Solution

The problem requires calculating the value of the test statistic tt for a hypothesis test.

Given Information:

  • Null Hypothesis: H0:μ=20H_0: \mu = 20
  • Alternative Hypothesis: H1:μ>20H_1: \mu > 20
  • Sample Size (nn) = 39
  • Sample Mean (xˉ\bar{x}) = 24
  • Sample Standard Deviation (ss) = 2

Formula for the t-test statistic:

The t-test statistic is calculated as: t=xˉμs/nt = \frac{\bar{x} - \mu}{s / \sqrt{n}} where:

  • xˉ\bar{x} is the sample mean,
  • μ\mu is the population mean under the null hypothesis,
  • ss is the sample standard deviation, and
  • nn is the sample size.

Substituting the values:

  1. Difference between the sample mean and the hypothesized mean: xˉμ=2420=4\bar{x} - \mu = 24 - 20 = 4
  2. Standard error of the mean: sn=23926.2440.32\frac{s}{\sqrt{n}} = \frac{2}{\sqrt{39}} \approx \frac{2}{6.244} \approx 0.32
  3. Calculating tt: t=40.3212.50t = \frac{4}{0.32} \approx 12.50

Answer:

The value of the test statistic tt is approximately 12.5012.50.

Would you like further details or explanations on hypothesis testing or related topics?

Related Questions:

  1. How do we interpret the results of a t-test in hypothesis testing?
  2. What is the significance of the degrees of freedom in a t-test?
  3. How do we determine the critical t-value for this test?
  4. What are Type I and Type II errors in hypothesis testing?
  5. How does sample size impact the test statistic and the conclusion of a hypothesis test?

Tip:

Always ensure your sample size is large enough to approximate the normal distribution in t-tests, which helps in obtaining reliable results.

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Math Problem Analysis

Mathematical Concepts

Hypothesis Testing
T-Statistic
Statistics

Formulas

t = (x̄ - μ) / (s / √n)

Theorems

Central Limit Theorem

Suitable Grade Level

Undergraduate Statistics