Question

A plant ecologist performs the following experiment. In a lathe house on campus, the ecologist fills 75 four liter plastic pots with soil. 25 are filled with native soil from a site near campus; 25 are filled with a mix of 50% native soil and 50% commercial potting soil; 25 are filled with 75% commercial potting soil and 25% playground sand. Four seeds of a local native annual plant are sown in each pot. The pots are watered daily. After germination, plants are thinned so that only one plant remains in each pot. The time to flowering, the height at flowering, and total seeds produced are recorded for each plant.

1. A hypothesis tested is

a) lathe houses affect growth in a native plant

b) soil type affects age at maturity in a native plant

c) watering affects seed number in a native plant

d) plant height at flowering affects soil type

2. The independent variable concerns

a) soil type

b) plant germination

c) pot size

d) seed number

3. Regarding the variable scales

a) the dependent variables are discrete/nominal and the independent variable is discrete/nominal

b) the dependent variables are continuous and the independent variable is continuous

c) the dependent variables are discrete/nominal and the independent variable is continuous

d) the dependent variables are continuous and the independent variable is discrete/nominal

4. Once the data is collected, the best statistical test given experimental design is

a) Linear Regression

b) t-Test

c) Chi-Square

d) Analysis of Variancev

Answer 1

1. Correct option will be B.

2. Correct option will be A.

An independent variable is the variable that is changed or controlled in a scientific experiment, nothing else in the experiment can change it.

3. Correct option is D.

4. Correct option will be C.

The Chi-Square test is commonly used to test relationship between categorical variables.

Thank you.