Answer each question for 100 points A local botanist believes that the town water supply contains contaminants that are killing the native plant life. She intends to make her case to the Board of Supervisors at the next town meeting in two months but wants to have heard data to support her case. She decides to conduct an experiment to test her theory. She begins by collecting 10 plant samples from the local park and places all 10 plants in a roped-off square area that receives ample light and will be undisturbed by park visitors. Next, she places 10 scraps of paper numbered 1 to 10 in a hat, then pulls the scraps of paper at random, numbers the plants 1 to 10 and divides them into two groups. For six weeks, she waters 5 of the plants (3, 5, 7, 9 and 10) using the town water supply and 5 of the plants (plants 1, 2, 4, 6, 8) using bottled, distilled water. During the six weeks, she asks her neighbor and fellow plant lover to keep records of leaf condition (color, texture, strength) and stem and root conditions by counting the number of yellowed spots, wilted leaves, and withered offshoots. At the end of six weeks, she asks her neighbor to evaluate the 10 plants and he reports that plants 3, 5, 9 and 10 are yellowed, withering and diseased.

a. What is the hypothesis in this situation?

b. Which group of plants is the experimental group? The control group?

c. What method did the researcher use to randomly assign the groups?

d. How was double blind procedure used?

e. What was the Independent Variable? The Dependent Variable?

f. What is the Operational Definition of the Independent Variable? The Dependent Variable?

g. What possible confounding variables might the researcher not have taken into account?

Answer and Explanation:

The. What is the hypothesis in this situation? The water from the city's water supply contains contaminants that harm the palntas. A hypothesis is an assumption about a certain phenomenon, which must be tested by a scientific experiment that shows that the hypothesis is true or false.

B. Which group of plants is the experimental group? The control group? The plants that received water from the city supply are the experimental group, while the plants that received distilled water are the control group. The experimental group is the one that receives the element that will be tested in the experiment, while the control group is the group that does not receive this element, but receives a neutral element that will not cause any changes in the natural form of that group.

c. What method did the researcher use to randomly assign the groups? A randomized block design was used, where the researcher divides the research elements into homogeneous groups with the same number of elements in each group.

d. How was double blind procedure used? This procedure was used when neither the researcher nor the studied plants knew the composition of the water used. This type of procedure occurs when neither the researcher nor the research object knows the variable being tested at the moment.

e. What was the Independent Variable? The Dependent Variable? The independent variable is the water in the city reservoir, while the dependent variable is the occurrence of degradation of the plants that were irrigated by this water.

f. What is the Operational Definition of the Independent Variable? The Dependent Variable? Independent variable is one that influences other variables for the appearance of a result. Dependent variable is that which is influenced to promote a measured result.

g. What possible confounding variables might the researcher not have taken into account? The composition of the soil where the plants were planted and the incidence of light can be a confusing variable. A confounding variable is one that is neither a dependent variable nor an independent variable, but can influence the results of the experiment.