Statistics

• What is the null hypothesis?

  The null hypothesis assumes there is no relationship,

  "There is no correlation between variable 1 and 2"
• What is an example of the null hypothesis?

  There is no correlation between length and mass of a blue whale.
• A conclusion for the null hypothesis?

  Our calculated value of spearman's rank correlation coefficient , rs (+0.834) is larger than the critical value of (0.59).

  There is less than 5% probability that the positive correlation between the length and mass of the whale is due to chance.

  We reject our null hypothesis.
• If there is no overlap of standard deviations, this suggests there is a significant difference between the total number of beetles at each farm.
• If there is overlap of standard deviations, this suggest there is no significant difference between the total number of beetles at each farm.
• What is the T-test?

  Comparing 2 means
• What is the null hypothesis for the t-test?

  "there is no significant difference between the means for group 1 and group 2"
• How do u calculate the degrees of freedom?

  (n1+n2)-2
• T Test conclusions- reject


  If the T value is bigger than the critical value from the table,

  we reject the null hypothesis,

  as there is less than 5% probability that the difference in means is due to chance.
• T test conclusions- accept


  If the calculated T value is smaller than the critical value from the table,

  we accept the null hypothesis,

  There is more than a 5% probability that the difference in means is due to chance.
• What is chi-squared/x^2?

  "There is no significant difference between observed and expected results"
• What is the null hypothesis for chi-squared?

  There is no significant difference between the observed (number of animals on each kind of sea weed) and the expected (amount of animals on each kind of seaweed)
• Chi-squared results- reject

  If the calculated x^2 value is bigger than the critical value from the table,

  we reject the null hypothesis,

  As there is a less than 5% probability that the results are due to chance.
• Chi-squared results- accept


  If the calculated x^2 value is smaller than the critical value from the table,

  We accept the null hypothesis,

  As there is more than a 5% probability that the results are due to chance.