What is pooled variance and why is it important? explain, Ask an Expert

Statistics

1. What is pooled variance and why is it important?

2. Explain what interval data is and give an example:

3. Write the formula for a problem that has 2 sample populations greater than 30 and the standard deviations are known and equal:

4. Write the formula for pooled variance.

5. Please analyze the following data using the T-test for Unpaired data:

A school district wants to determine if the girls are equal to boys in test scores. They took a random sample of 22 8th grade girls and 24 8th grade boys. The district looked at recent CAT scores and found the mean score for girls to be xbar1 = 25 and the mean score for boys to be xbar2 = 26. The standard deviation for the girls is s1 = 2.2 and for the boys the standard deviation is s2 = 3.4. Is the school district correct in assuming the girls are equal in performance to boys. They are 95% sure their assumption is correct.

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Category:- Statistics and Probability
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