Chi Square

How do you find degrees of freedom?

• one less than the possible genotypes
• one less than the possible phenotypes
• total number divided 2
• total number times 2

Tags

NGSS.HS-LS4-3

What is the purpose of a Chi-Square test?

• To determine if there is a significant difference between the observed and expected values in an experiment.

• To determine if there is a statistically significant difference between the observed and expected values in an experiment.

• To do extra math.

• To conclusively prove that your null hypothesis is true or false.

Find the degrees of freedom.

• 4
• 5
• 6
• 7

Gregor Mendel was experimenting with peas and exploring the basics of genetics. He knew that green (G) is dominant over yellow (g) peas. In one experiment, he crossed a heterozygous green pea with a homozygous yellow pea. In the F1 generation he obtained a total of 400 peas out of which 180 were green and 220 were yellow.

a. Calculate the chi-square to the nearest tenth.

c. Explain if the null hypothesis can be kept or rejected.

• x² = 4; Null hypothesis can be rejected because chi-square is greater than the critical value of 3.84.

• x² = 4.5; Null hypothesis can be kept because chi-square is less than the critical value of 5.99

• x² = 2; Null hypothesis can be rejected because chi-square is less than the critical value of 5.99

• x² = 4; Null hypothesis can be kept because chi-square is greater than the critical value of 3.84

If the χ² _critical value = 5.99 and the

χ² _calculated value = 7.35, what is the conclusion

• Reject Ho

• Do not reject Ho

• there is not enough info to decide

• The conclusion can only be made if we also know the p-value

What is the null hypothesis?

• Injury type is independent of position played

• Injury type is dependent on the position played independent

• Injury type is correlated to position played.

This symbol denotes the null hypothesis

• Null hypothesis

• Alternative Hypothesis

• H₀

• H_a