How to Find the P-Value and Test Statistic in StatCrunch?

TL;DR

To find the P-value and test statistic for a two-sample T test in StatCrunch, enter your sample data, ensuring to select 'two samples with summary' and uncheck 'pool variances.' For the comparison, choose the direction of the hypothesis based on the problem statement, then click compute to get the test statistic and P-value outputs.

Transcript

in this video we're going to go over how to find the P value and test statistic in a two sample T Test so let's focus on problem 13 so it says a sample of 10 regions in New England had a mean violent crime rate of 3.51 and a standard deviation of 81 so already in the first sentence you see it's giving us the sample standard deviation so that tells ... Read More

Key Insights

• 🏆 Two sample T tests are used to compare means between two independent samples.
• 🦖 When the sample standard deviations are provided, T statistics are used assuming unequal variances.
• 💁 Inputting the sample information correctly in StatCrunch is crucial for obtaining accurate test results.
• 🏆 The direction of the hypothesis test can usually be determined from the problem statement.
• 🏆 The test statistic represents the difference in means, and the P value indicates the statistical significance of this difference.
• 🏆 Unchecking the "pool variances" option in StatCrunch is important for T tests assuming unequal variances.
• 💁 The P value provides information about the likelihood of observing the data given the null hypothesis.

Questions & Answers

Q: How do you determine whether to use T statistics or a different method in a two sample T test?

In a two sample T test, if the problem provides the sample standard deviations, you should use T statistics. This indicates that the test will be performed assuming unequal variances.

Q: How do you input the sample information in StatCrunch to compute the test statistic and P value?

To input the sample information in StatCrunch, go to "Stat" and then "T stats". Select "Two Samples" and "With summary". Fill in the sample sizes, means, and standard deviations for both samples. Make sure to uncheck the "pool variances" box.

Q: How can you determine the direction of the hypothesis test from the problem statement?

Usually, you can determine the direction of the hypothesis test from the last sentence of the problem. In this example, it asks if the data indicates that the violent crime rate in New England is lower than in the Rocky Mountains, so you would select "less than".

Q: What is the significance of the test statistic and P value in the two sample T test?

The test statistic represents the difference between the sample means relative to the variability within the samples. The P value indicates the likelihood of observing such a difference assuming the null hypothesis is true. A lower P value suggests stronger evidence against the null hypothesis.

Summary & Key Takeaways

• The video explains how to find the P value and test statistic in a two sample T test using StatCrunch.

• The example problem focuses on the comparison of violent crime rates between New England and the Rocky Mountains.

• The video demonstrates step-by-step instructions on filling in the necessary information in StatCrunch to compute the test statistic and P value.