Math Problem Statement

you wish to test the following claim () at a significance level of .02.

H: u = 79.8 H: u>79.8

You believe the population is normally distributed, but you do not know the standard deviation. You obtain a sample of size n=14 with meanm=90.8 and a standard deviation of sd=10.6.

What is the test statistic for this sample? (Report answer accurate to three decimal places.) test statistic =

what is the p-value for this sample:

Solution

We are conducting a one-sample t-test to test the claim. Since the population standard deviation is unknown and the sample size is small (n=14n = 14), we will use the t-distribution.

Step 1: Formulate the hypotheses

  • Null hypothesis (H0H_0): μ=79.8\mu = 79.8
  • Alternative hypothesis (H1H_1): μ>79.8\mu > 79.8 (right-tailed test)

Step 2: Calculate the test statistic

The formula for the test statistic in a t-test is:

t=xˉμ0snt = \frac{\bar{x} - \mu_0}{\frac{s}{\sqrt{n}}}

Where:

  • xˉ\bar{x} is the sample mean (90.8)
  • μ0\mu_0 is the population mean under the null hypothesis (79.8)
  • ss is the sample standard deviation (10.6)
  • nn is the sample size (14)

Substitute the values:

t=90.879.810.614t = \frac{90.8 - 79.8}{\frac{10.6}{\sqrt{14}}}

First, compute the denominator:

10.614=10.63.74172.834\frac{10.6}{\sqrt{14}} = \frac{10.6}{3.7417} \approx 2.834

Now compute the t-statistic:

t=90.879.82.834=112.8343.882t = \frac{90.8 - 79.8}{2.834} = \frac{11}{2.834} \approx 3.882

Thus, the test statistic is approximately:

t3.882t \approx 3.882

Step 3: Find the p-value

To find the p-value, we look up the value of t=3.882t = 3.882 in a t-distribution table with n1=141=13n - 1 = 14 - 1 = 13 degrees of freedom.

Using statistical software or a t-distribution table, the one-tailed p-value for t=3.882t = 3.882 with 13 degrees of freedom is approximately:

p0.0012p \approx 0.0012

Final Answers:

  • Test statistic: t3.882t \approx 3.882
  • p-value: p0.0012p \approx 0.0012

Would you like further clarification or details?

Here are some related questions:

  1. How do you interpret the p-value in hypothesis testing?
  2. What are the critical values for a t-test at the 0.02 significance level?
  3. How does sample size affect the t-statistic?
  4. What assumptions are necessary for conducting a t-test?
  5. What is the difference between a one-tailed and two-tailed t-test?

Tip: Always check if the assumptions for a t-test are met (e.g., normality of the population distribution).

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Math Problem Analysis

Mathematical Concepts

Hypothesis Testing
t-Distribution
One-Sample t-Test

Formulas

t = (x̄ - μ0) / (s / √n)
p-value from t-distribution table with degrees of freedom = n - 1

Theorems

Central Limit Theorem
Student's t-Distribution

Suitable Grade Level

College (Statistics, Introductory)