Math Problem Statement

(b) Compute the P-value. Round the answer to at least four decimal places.

Compute the P-value. Round the answer to at least four decimal places.

Solution

To compute the P-value for the test involving μd=μ1μ2\mu_d = \mu_1 - \mu_2 based on the provided data, we will perform the following steps:

  1. Calculate the differences (di=x40°Fx80°Fd_i = x_{40°F} - x_{80°F}).
  2. Compute the mean of the differences (dˉ\bar{d}).
  3. Compute the standard deviation of the differences (sds_d).
  4. Perform a t-test to find the test statistic (tt).
  5. Use the t-distribution to calculate the P-value.

Let me calculate it for you.import numpy as np from scipy.stats import t

Data for 40°F and 80°F emissions

emissions_40 = np.array([851.4, 775.8, 872.8, 937.2, 832.5, 880.2, 944.5, 806.9, 763.0, 933.5]) emissions_80 = np.array([839.7, 795.8, 867.9, 837.0, 817.8, 844.1, 830.6, 750.1, 796.1, 882.1])

Calculate differences

differences = emissions_40 - emissions_80

Compute mean and standard deviation of differences

mean_diff = np.mean(differences) std_diff = np.std(differences, ddof=1) # Sample standard deviation n = len(differences) # Number of paired observations

Test statistic (t-value)

t_stat = mean_diff / (std_diff / np.sqrt(n))

Degrees of freedom

df = n - 1

Compute the two-tailed p-value

p_value = 2 * (1 - t.cdf(abs(t_stat), df))

mean_diff, std_diff, t_stat, p_value(33.65999999999999, 47.98993412975036, 2.218012338868391, 0.053738082618467686)(33.65999999999999, 47.98993412975036, 2.218012338868391, 0.053738082618467686)successThe results are as follows:

  • Mean difference (dˉ\bar{d}): 33.6600
  • Standard deviation of differences (sds_d): 47.9900
  • Test statistic (tt): 2.2180
  • P-value: 0.0537

Would you like to delve deeper into interpreting the results?

Related Questions:

  1. What is the null hypothesis in this test?
  2. How do we determine statistical significance for this P-value?
  3. Can we conclude that temperature impacts NOx emissions significantly?
  4. Should we conduct a one-tailed test instead?
  5. How does sample size affect the outcome of this test?

Tip: Ensure your significance level (α\alpha) is predetermined before interpreting the P-value.

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Math Problem Analysis

Mathematical Concepts

Hypothesis Testing
Paired Sample t-Test
Descriptive Statistics

Formulas

Difference d_i = x_{40°F} - x_{80°F}
Mean difference \(\bar{d}\) = (1/n) \sum d_i
Standard deviation of differences \(s_d\) = \sqrt{(1/(n-1)) \sum (d_i - \bar{d})^2}
Test statistic t = \(\bar{d} / (s_d / \sqrt{n})\)
P-value from the t-distribution

Theorems

t-Distribution
Central Limit Theorem

Suitable Grade Level

Undergraduate Statistics