Math Problem Statement

Find the p-value if left-sided test, t-distribution, n = 45, Test Statistic = -2.5

Solution

The problem given is a hypothesis test question asking for the p-value. Here is a breakdown of the relevant information extracted from the image:

  • Test Type: Left-sided test
  • Distribution: t-distribution
  • Sample Size (n)(n): 45
  • Test Statistic: 2.5-2.5

Step-by-Step Solution

To find the p-value for a left-tailed test with a tt-distribution:

  1. Degrees of Freedom (df): For a t-test, degrees of freedom is n1n - 1. df=451=44df = 45 - 1 = 44

  2. Using the Test Statistic: Since it's a left-sided test, the p-value is the probability that a t-distributed random variable with 44 degrees of freedom is less than 2.5-2.5.

  3. Finding the p-value: You would typically use a t-distribution table or statistical software to find this value.

    For a tt-score of 2.5-2.5 with 44 degrees of freedom, the approximate p-value is 0.007 (as given in the image).

Conclusion

If this p-value is compared against a significance level α\alpha, such as α=0.05\alpha = 0.05, you would reject the null hypothesis because 0.007<0.050.007 < 0.05.

Would you like further details on how to calculate or interpret this result?


Further Questions:

  1. What does the p-value represent in the context of hypothesis testing?
  2. How does the choice between a one-tailed and two-tailed test affect the p-value?
  3. Why do we use degrees of freedom in the t-distribution?
  4. What conditions must be met to use a t-distribution instead of a z-distribution?
  5. How would the interpretation change if this were a two-tailed test?

Tip: For hypothesis testing, always verify the type of test (one-tailed or two-tailed) and check if the conditions match the assumptions of the test being used (like normality for small samples in t-tests).

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Math Problem Analysis

Mathematical Concepts

Hypothesis Testing
T-distribution
P-value Calculation

Formulas

Degrees of Freedom (df) = n - 1
P-value for left-sided t-test

Theorems

Hypothesis Testing Theory

Suitable Grade Level

Undergraduate Statistics