ACT Science Practice Test

A bar graph shows the average rainfall in inches for four months in a given year: January (5 inches), February (3 inches), March (7 inches), and April (4 inches). What is the total rainfall for the first four months?

A scatter plot shows a positive correlation between temperature and plant growth. If the temperature increases by 10 degrees, how much does plant growth increase if the correlation coefficient is 0.9?

A graph shows the volume of a gas versus its pressure at a constant temperature, indicating an inverse relationship. If the pressure is doubled, what happens to the volume?

A bar graph shows the frequency of four different bacteria types in a lab. If the graph shows 12 Type A, 8 Type B, 5 Type C, and 15 Type D bacteria, what percentage of the total bacteria are Type B?

A line graph depicts the number of customers in a store during business hours. The number starts at 20 customers, peaks at 80 customers, and then decreases to 40 customers. If this pattern occurs within a 12-hour period, what is the average change in customer count per hour over the first 6 hours?

A scatter plot shows a positive correlation between study hours and test scores for a class of students. If a student increases their study time by 5 hours and sees an average increase of 10 points in their test score, what can be inferred about the relationship between study time and test scores?

A scatter plot shows a negative correlation between temperature and fish population in a lake. If the temperature increases by 10 degrees, how much does the fish population decrease if the correlation coefficient is -0.75?

A table shows the data for the population of a certain species of birds in five different regions: Region A (50 birds), Region B (40 birds), Region C (60 birds), Region D (55 birds), and Region E (45 birds). What is the median population for these regions?

A line graph shows the speed of a train over time. It starts at 0 km/h, accelerates to 90 km/h within 15 minutes, and then decelerates to 60 km/h over the next 10 minutes. What is the average acceleration during the first 15 minutes?

A table lists the pH values for five different substances: Substance A (7.5), Substance B (8.0), Substance C (6.5), Substance D (9.0), and Substance E (7.0). What is the mode pH value among these substances?

A bar graph displays the frequency of four different species of insects in a forest. If the graph shows 50 Species A, 30 Species B, 40 Species C, and 60 Species D, what percentage of the total is Species C?

A scatter plot shows a linear relationship between hours of exercise and weight loss. If a person exercises for 10 hours and loses 5 kg, how much weight is expected to be lost by a person who exercises for 30 hours?

A graph shows the growth of a tree over a 10-year period. The tree's height begins at 2 meters, grows to 8 meters over 5 years, and reaches 10 meters by the end of the 10-year period. What is the average rate of growth during the first 5 years?

A researcher is conducting an experiment on the growth of bacteria in petri dishes. If a petri dish has bacteria that doubles every 2 hours, how many times will the bacteria double in 8 hours?

A scientist studies a new material and notices that its density is influenced by its temperature. Given that density is mass per unit volume, if the temperature is increased, which of the following outcomes would most likely be observed?

A scientist observes that plants grown under certain conditions produce more fruit. If these plants are grown under 10 hours of light daily, how would the results likely change if the plants are subjected to 12 hours of light daily?

In an experiment, a scientist uses varying amounts of salt to determine its effect on boiling point. If the boiling point of a solution increases with more salt, what is the most likely reason?

A chemical reaction occurs in a closed system, and a gas is released as a byproduct. If the gas is contained in a balloon, what happens to the balloon's volume if the gas is allowed to expand in a larger container without changing pressure or temperature?

In an experiment to determine the optimal growth conditions for bacteria, scientists vary the temperature in a series of test tubes containing bacteria. If the bacteria grow best at a specific temperature, what would you expect to see in the results?

An experiment involves dropping a metal object into a beaker filled with a chemical solution. If the metal starts to dissolve upon contact with the solution, which of the following best explains this observation?

A scientist observes the migration patterns of birds over a 10-year period. If the number of birds migrating annually decreases, which of the following is the most likely cause?

A researcher is conducting an experiment to test plant growth under different soil conditions. If one group of plants receives soil with high nitrogen content while the other group receives regular soil, what would likely be observed in the results?

A scientist observes a population of insects over a year. If the population decreases during the colder months and increases during the warmer months, what might be the best explanation for this pattern?

A scientist is investigating the effects of different soil types on plant growth. She uses three types of soil: sandy, loamy, and clay. She plants the same species of plant in each type of soil and measures their growth over a month. The plants in the loamy soil grow the tallest. Which of the following can be inferred from this experiment?

A researcher wants to determine whether a specific vitamin supplement affects muscle growth. She uses two groups of subjects: one group takes the supplement daily, while the other does not. After 12 weeks, she measures the muscle growth in both groups. The group taking the supplement has significantly more muscle growth. Which of the following is the best conclusion from this study?

A laboratory conducts an experiment to test the effect of varying light intensities on the rate of photosynthesis in plants. The results indicate that photosynthesis increases with light intensity up to a certain point, after which it levels off. What can be concluded from these results?

An experiment measures the impact of water temperature on the rate of chemical reactions in a solution. The results show that the rate of reactions increases with water temperature, but then sharply decreases at a certain point. What inference can be made from this result?

A group of scientists is studying the migration patterns of birds. They set up tracking devices on several species and observe their migration routes. They notice that all the observed species follow similar paths during migration. Which of the following could be inferred from this observation?

An experiment is conducted to test the effect of varying pH levels on plant growth. The results indicate that plant growth is optimal within a specific pH range but declines significantly outside that range. What can be inferred from these results?

A scientist wants to test if varying amounts of fertilizer affect plant growth. She applies different amounts of fertilizer to three groups of plants and measures their growth. The group with the highest amount of fertilizer shows reduced growth. What can be inferred from this experiment?

A team of researchers is investigating whether varying sound frequencies affect plant growth. They expose plants to different frequencies and measure growth over time. The plants exposed to higher frequencies show reduced growth. What inference can be drawn from these results?

An experiment is conducted to test whether varying carbon dioxide (CO2) levels affect plant growth. Plants are placed in chambers with different CO2 concentrations, and their growth is monitored. The results show that plant growth increases with higher CO2 levels but plateaus after a certain point. What can be concluded from these results?

A group of scientists is studying the impact of various water salinity levels on fish behavior. They place fish in tanks with different salinity levels and monitor their movement and feeding patterns. The fish in the highest salinity tank exhibit decreased activity and reduced feeding. What can be inferred from this experiment?

An experiment is conducted to test the effect of various light colors on plant growth. Plants are exposed to different light colors, and their growth is measured. Plants exposed to red light show the most significant growth, while those exposed to blue light grow the least. What inference can be made from this experiment?

A team of researchers is testing the impact of various humidity levels on plant growth. Plants are placed in controlled environments with different humidity levels and their growth is measured. The plants in environments with moderate humidity levels grow best, while those in very high or very low humidity environments grow poorly. What inference can be drawn from these results?

A researcher is investigating the impact of different soil compositions on water retention. He tests several soil samples with varying clay, sand, and silt compositions. The soil sample with the highest clay content retains the most water, while those with higher sand content retain the least. What can be concluded from these results?

A scatter plot shows a relationship between exercise duration and energy levels. If a person exercises for 30 minutes and their energy level increases by 15 units, how much is expected to increase if they exercise for 60 minutes?

A table shows the production of different types of fruits in a farm over a year: 200 kg of apples, 150 kg of oranges, 100 kg of bananas, and 250 kg of grapes. What percentage of the total production is made up of apples?

A bar graph shows the number of books read by four different students over a year: Alice (20 books), Bob (30 books), Carol (40 books), and David (50 books). What is the average number of books read per student?

A table shows the height of five different trees in a park: Tree A (10 meters), Tree B (15 meters), Tree C (20 meters), Tree D (12 meters), and Tree E (18 meters). What is the median height of these trees?