practice test

What is the primary goal of science?
- A) To create new technology
- B) To systematically understand the natural world through observation, experimentation, and reasoning
- C) To solve all human problems
- D) To memorize facts about the world
  Answer: B
Which of the following best describes inductive reasoning?
- A) Making predictions based on general principles
- B) Drawing specific conclusions from a general observation
- C) Making generalizations based on specific observations
- D) Creating laws from experiments
  Answer: C
What is the key difference between qualitative and quantitative observations?
- A) Qualitative observations use numbers, while quantitative use descriptions
- B) Quantitative observations use numbers, while qualitative use descriptions
- C) Both use numerical data
- D) Both use descriptive data
  Answer: B
In an experiment, which variable is deliberately manipulated by the researcher?
- A) Dependent variable
- B) Constant variable
- C) Independent variable
- D) Control variable
  Answer: C
What is the null hypothesis (H₀) in an experiment?
- A) A hypothesis that suggests a significant effect
- B) A prediction that no significant relationship exists between variables
- C) The hypothesis being tested in an experiment
- D) A well-established scientific theory
  Answer: B

A scientific law provides an explanation for why certain phenomena happen.
Answer: False (It describes observable phenomena, but does not explain why they happen.)
If error bars on a graph overlap, the difference between data sets may not be statistically significant.
Answer: True

What is a hypothesis and how should it be structured?
Answer: A hypothesis is a proposed explanation or prediction that can be tested through experimentation. It is typically structured as "If [cause], then [effect], because [rationale]."
What is the purpose of a positive control in an experiment?
Answer: A positive control is used to ensure the experimental setup works by showing a known positive result.
What does standard deviation measure in a data set?
Answer: Standard deviation measures how spread out the data points are from the mean. A higher standard deviation means greater variability in the data.

The independent variable is the factor that is deliberately _______ by the researcher in an experiment.
Answer: manipulated
In a normal distribution, _______ of the data falls within 1 standard deviation of the mean.
Answer: 68%

Warm up questions:

1- What is the chi-square test used for?

It’s used to check the difference between what you observe and what you expect, wether its due to chance or a factor at play.

2- How do you calculate chi-square?

chi square = sum of (observe value- expected value)^squared, over expected value

3- When do we use error bars?

we use error bars on graphs to show how uncertain or spread out the data is

4- What do error bars show?

error bars show variability or uncertainty in data. They can represent standard deviation or how confident we are in a result.

5- What does standard deviation measure?

It shows how spread out the data is from the mean. A small standard deviation means the data points are close together.

6- What is the difference between error bars and chi square?

Chi-Square: Tests if two things are related.

Error bars: Visualize the variability or uncertainty in data.

7- What is a null hypothesis ?

It’s the assumption that there’s no effect or difference.

8- When do you accept your null hypothesis ? for chi square test? Error bars?

Chi-Square: If the p-value is high (above 0.05), you accept that there’s no relationship.

Error bars: If error bars overlap, you likely accept there’s no big difference.

9- When do you reject your null hypothesis? for chi square test? Error bars?

Chi-Square: If the p-value is low (below 0.05), you reject it and say there is a relationship.

Error bars: If error bars don’t overlap, you might reject it and say there’s a difference.