# Experiment Design Analysis - short set A

## Directions:

For each scenario answer these questions on a separate sheet of paper:

- What is the question ?
- What is a possible hypothesis?
- Manipulated variable =
- Responding variable =
- Controlled variables =
- Does this experiment have a control? If so, what is the control?
- Is this quantitative or qualitative data ?

## Plant Growth

Shamecca is doing a plant growth experiment. She wants to measure the effect on plant growth of adding different amounts of fertilizer to the potting soil. She gives the plants the same amount of soil, water and sunlight. After 6 weeks she measures the height of the plants and records this data :

- 1
^{st}pot : 0 grams fertilizer = 30 cm plant height - 2
^{nd}pot : 1 grams fertilizer = 45 cm plant height - 3
^{rd}pot : 2 grams fertilizer = 60 cm plant height - 4
^{th}pot : 3 grams fertilizer = 50 cm plant height

## Studying

Allen wants to see if studying will improve his science grade. Each week he studies a little more and looks to see if his grade goes up for that week. Each week he tries to get enough sleep and doesn't eat strange foods. Work is going OK so he doesn't have that stress in his life.

- 1
^{st}week : 0 hours study time = F - 2
^{nd}week : 2 hours study time = C - 3
^{rd}week : 3 hours study time = B - 4
^{th}week : 4 hours study time = B+

## Mileage

Marcia heard that premium unleaded gasoline gives her better gas mileage than regular unleaded. In her experiment, she filled up with tank # 1 right before she drove to Seattle. With tanks 2, 3 and 4 Marcia drove to school and work in Oak Harbor.

- 1
^{st}tank : premium yields 22 mpg - 2
^{nd}tank : premium yields 20 mpg - 3
^{rd}tank : regular yields 20 mpg - 4
^{th}tank : regular yields 19 mpg

- Also: Why did Marcia uses two tanks for each gasoline type?

## Fossils and cliff depth

Jose observed that different kinds and amounts of fossils were present in a cliff behind his house. He wondered what changes in fossils content occurred from the top to the bottom of the bank. He marked the bank at five positions: 5, 10, 15, 20 and 25 meters from the top. He removed one bucket of soil from each position and determined the kind and number of fossils in each sample.

- First: make a sketch of the fossils in the cliff:

## Compost and bean plants

John's biology class investigated the effect of recycled products on plant growth. John's lab group compared the effect of different aged grass compost on bean plants. Because decomposition is necessary for the release of nutrients, the group hypothesized that older grass compost would produce taller bean plants. Three flats of bean plants, with 25 plants per flat, were grown for 5 days. The flats were then given these treatments:

- Flat A: 450 g of 3 month old compost.
- Flat B: 450 g of 6 month old compost.
- Flat C: 0 g of compost.

At the end of 30 days, the group recorded the height of the plants (cm).

- First: make a sketch of the three flats indicating the amounts and age of the compost: