Question

If the number of cigarettes smoked increases, then the risk for lung cancer increases. Independent variable: _______ Dependent variable: _______ If the number of sharks swimming in a coastal region increases, then the number of shark attacks on humans will also increase. Independent variable: _______ Dependent variable: _______ If the amount of milk a person drinks increases, the strength of his or her bones will stay the same. Independent variable: _______ Dependent variable: _______

Answer 1

Lab: Heart Rate

Part A: Identifying Variables

The dependent variable happens as a result of values/changes associated with the independent variable.

Independent variable: number of cigarettes smoked

Dependent variable: risk for lung cancer

Independent variable: number of sharks swimming in a coastal region

Dependent variable: number of shark attacks on humans

Independent variable: amount of milk a person drinks

Dependent variable: the strength of his or her bones

Part B: Heart Rate

Hypothesis: If I hold my breath for 30 seconds, then my heart rate will

(choose 1) increase/decrease.

Independent variable: holding my breath

Dependent variable: heart rate

Part C:

The heart rate decreases because oxygen exchange in the lungs decreases.

This depends on what you chose for heart rate in the hypothesis. If you said the heart rate decreases after holding your breath, and the results showed the heart rate decreased, then the hypothesis is supported. If you said the heart rate decreases after holding your breath, and the results showed the heart rate increased, then you refuted the hypothesis.

Heart rate can change due to an increase or decrease in activity, moving positions such as sitting and standing, and emotions.

Example: Increase in activity—jumping jacks

Hypothesis: If I do five jumping jacks, then my heart rate will increase.

Test hypothesis. You can use the average resting heart rate from the previous experiment. If you do an experiment with an increase in physical activity like jumping jacks, then your data will reflect an increase in heart rate because the body requires more energy, which requires more oxygen, increasing the overall flow of blood in the body.

Support or refute the hypothesis based on the results. The hypothesis is supported if it aligns with the observed results. The hypothesis is refuted if the results don’t match the statement based on the variables.

Testing more than one variable at a time makes it difficult to interpret the results and support or refute the hypothesis. With one variable, the results can be associated with changes to that variable. To get the most reliable data to support or refute a hypothesis, an experiment should be completed several times to see if the results show the same trends.

Step-by-step explanation:

Penn Foster

Answer 2

Complete Question:

Part A: Identifying Variables

Read the following hypotheses and identify the variables.

If the number of cigarettes smoked increases, then the risk for lung cancer increases.

Independent variable: _______

Dependent variable: _______

If the number of sharks swimming in a coastal region increases, then the number of shark attacks on humans will also increase.

Independent variable: _______

Dependent variable: _______

If the amount of milk a person drinks increases, the strength of his or her bones will stay the same.

Independent variable: _______

Dependent variable: _______

Answer/Explanation:

Dependent variables are variables that is dependent on the independent variables. That is, it is the variable that changes as the independent variable changes.

Depedent variable is the main interest if a researcher. It is the variable that is measured in a research work.

In the above given hypotheses, the dependent and independent variables are shown below:

1. "risk for lung cancer" is dependent on the "number of cigarettes smoked".

"Risk for lung cancer" => dependent variable

Number of cigarettes => independent variable

2. "number of shark attacks on humans" is dependent on "number of sharks swimming".

Dependent variable => number of shark attacks on humans

Independent variable => number of sharks swimming

3. Dependent variable => strength of bone

Independent variable => amount of milk a person drinks