Question

2. We are interested in determining whether the diving depth of sea otters depends on

whether the animal has eaten, and we predict that diving depth will be lower after it eats than

before. We attach time depth recorders to 50 otters and watch them forage. Only two

observations of diving are made per otter -- one before it eats, then one after —and we realize

after collecting the data that there is considerable variation among otters in diving behavior.

a. What’s the dependent variable?

b. What’s the predictor or independent variable?

c. What’s the null hypothesis?

d. What type of test should we use – a paired t-test or an independent one? Why?

e. What type of test should we use – one tailed t-test or two-tailed? Why?

Answer 1

Q.A) The variable in a functional relation whose value is dependent upon, or influnceed by an independent variable.

Q.B)An independent variable, sometimes called an experimental or predictor variable, is a variable that is being manipulated in an experiment in order to observe the effect on a dependent variable, sometimes called an outcome variable.

Q.C) The hypothesis is that there is no significant diffrence between specified populations, any observed difference being due to sampeling or experimental error.