Which variable is the one that is used for comparison (not manipulated) in a scientific investigation?

Different rose bushes are grown in a greenhouse for two months. The number of flowers on each bush is counted at the end of the experiment. Identify the dependent variable.

Different rose bushes are grown in a greenhouse for two months. The number of flowers on each bush is counted at the end of the experiment. Identify the independent variable.

You water three sunflower plants with salt water. Each plant receives a different concentration of salt solutions. A fourth plant receives pure water. After a two week period, the height is measured. Identify the dependent variable.

You water three sunflower plants with salt water. Each plant receives a different concentration of salt solutions. A fourth plant receives pure water. After a two week period, the height is measured. Identify the independent variable.

You water three sunflower plants with salt water. Each plant receives a different concentration of salt solutions. A fourth plant receives pure water. After a two week period, the height is measured. Identify the control variable.

Three redwood trees are kept at different humidity levels inside a greenhouse for 12 weeks. One tree is left outside in normal conditions. The heights of the trees are measured once a week. Identify the control variable.

Three redwood trees are kept at different humidity levels inside a greenhouse for 12 weeks. One tree is left outside in normal conditions. The heights of the trees are measured once a week. Identify the dependent variable.

Three redwood trees are kept at different humidity levels inside a greenhouse for 12 weeks. One tree is left outside in normal conditions. The heights of the trees are measured once a week. Identify the independent variable.

Pea plant clones are giving different amounts of water for three-week period. The first pea plant receives 400 milliliters a day. The second pea plant receives 200 milliliters a day. The third pea plant receives 100 milliliters a day. The fourth pea plant does not receive any extra water: the plant only receives natural ways of receiving water. The heights of the pea plants are recorded daily. Identify the independent variable.

Pea plant clones are giving different amounts of water for three-week period. The first pea plant receives 400 milliliters a day. The second pea plant receives 200 milliliters a day. The third pea plant receives 100 milliliters a day. The fourth pea plant does not receive any extra water: the plant only receives natural ways of receiving water. The heights of the pea plants are recorded daily. Identify the control variable.

Pea plant clones are giving different amounts of water for three-week period. The first pea plant receives 400 milliliters a day. The second pea plant receives 200 milliliters a day. The third pea plant receives 100 milliliters a day. The fourth pea plant does not receive any extra water: the plant only receives natural ways of receiving water. The heights of the pea plants are recorded daily. Identify the dependent variable.

One tank of gold fish is fed the normal amount of food once a day. A second tank is fed twice a day. A third tank is fed four times a day during a six week study. The fish’s weight is recoded daily. Identify the dependent variable.

One tank of gold fish is fed the normal amount of food once a day. A second tank is fed twice a day. A third tank is fed four times a day during a six week study. The fish’s weight is recoded daily. Identify the independent variable.

One tank of gold fish is fed the normal amount of food once a day. A second tank is fed twice a day. A third tank is fed four times a day during a six week study. The fish’s weight is recoded daily. Identify the control variable.

Strawberry plant clones are given different amounts of water for a 3-week period. First strawberry plant receives 400 milliliters (ml) a day. The second strawberry plant receives 200ml a day. The third strawberry plant receives 100ml a day. The fourth strawberry plant does not receive any extra water; this plant only receives natural ways of receiving water. The height of the strawberry plants is recorded daily. Identify the control variable.

Strawberry plant clones are given different amounts of water for a 3-week period. First strawberry plant receives 400 milliliters (ml) a day. The second strawberry plant receives 200ml a day. The third strawberry plant receives 100ml a day. The fourth strawberry plant does not receive any extra water; this plant only receives natural ways of receiving water. The height of the strawberry plants is recorded daily. Identify the dependent variable.

Strawberry plant clones are given different amounts of water for a 3-week period. First strawberry plant receives 400 milliliters (ml) a day. The second strawberry plant receives 200ml a day. The third strawberry plant receives 100ml a day. The fourth strawberry plant does not receive any extra water; this plant only receives natural ways of receiving water. The height of the strawberry plants is recorded daily. Identify the independent variable.

Strawberry plant clones are given different amounts of water for a 3-week period. First strawberry plant receives 400 milliliters (ml) a day. The second strawberry plant receives 200ml a day. The third strawberry plant receives 100ml a day. The fourth strawberry plant does not receive any extra water; this plant only receives natural ways of receiving water. The height of the strawberry plants is recorded daily. Identify the control variable.

A student wanted to test how the mass of a paper airplane affected the distance it would fly. Paper clips were added before each test flight. For the first trial, the paper airplane had zero paper clips. For the second trial, the paper airplane had 1 paper clip. For the third trial, the paper airplane had 2 paper clips. For the fourth trial, the paper airplane had 3 paper clips. As each paper clip was added, the plane was tested to determine how far it would fly. Identify the independent variable.

A student wanted to test how the mass of a paper airplane affected the distance it would fly. Paper clips were added before each test flight. For the first trial, the paper airplane had zero paper clips. For the second trial, the paper airplane had 1 paper clip. For the third trial, the paper airplane had 2 paper clips. For the fourth trial, the paper airplane had 3 paper clips. As each paper clip was added, the plane was tested to determine how far it would fly. Identify the dependent variable.

A student wanted to test how the mass of a paper airplane affected the distance it would fly. Paper clips were added before each test flight. For the first trial, the paper airplane had zero paper clips. For the second trial, the paper airplane had 1 paper clip. For the third trial, the paper airplane had 2 paper clips. For the fourth trial, the paper airplane had 3 paper clips. As each paper clip was added, the plane was tested to determine how far it would fly. Identify the control variable.

Two groups of students were tested to compare their speed working math problems when using calculators. Each group was given the same problems. One group used calculators and the other group computed without calculators. Identify the control variable.

Two groups of students were tested to compare their speed working math problems when using calculators. Each group was given the same problems. One group used calculators and the other group computed without calculators. Identify the independent variable.

Two groups of students were tested to compare their speed working math problems when using calculators. Each group was given the same problems. One group used calculators and the other group computed without calculators. Identify the dependent variable.