Worksheet on analyzing and interpreting scientific data with graphs and questions.

Problem Analysis:

The task involves analyzing and interpreting scientific data presented in three different types of graphs: a line graph, a bar graph, and a pie chart. The goal is to answer specific questions related to each graph.

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Graph 1: Line Graph

#### Description:
- The line graph shows the growth rate of bacteria (in percentage) over time (hours).
- The x-axis represents time in hours, and the y-axis represents the growth rate in percentage.
- Key features:
- The growth rate increases sharply from hour 0 to hour 4.
- It reaches a peak at hour 4.
- After hour 4, the growth rate starts to decline gradually.

#### Question:
> What is the approximate growth rate of bacteria at hour 3?

#### Solution:
1. Locate the point on the graph corresponding to hour 3 on the x-axis.
2. Follow the vertical line up to the curve and then read the value on the y-axis.
3. From the graph, the growth rate at hour 3 appears to be approximately 75%.

#### Answer:
$$
\boxed{75\%}
$$

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Graph 2: Bar Graph

#### Description:
- The bar graph shows the number of students who prefer different modes of transportation to school.
- The x-axis lists the modes of transportation: Bus, Car, Bicycle, and Walking.
- The y-axis represents the number of students.
- Key features:
- Bus: Approximately 40 students.
- Car: Approximately 30 students.
- Bicycle: Approximately 20 students.
- Walking: Approximately 10 students.

#### Question:
> Which mode of transportation is preferred by the most students?

#### Solution:
1. Compare the heights of the bars for each mode of transportation.
2. The tallest bar corresponds to the mode preferred by the most students.
3. From the graph, the tallest bar is for Bus, with approximately 40 students.

#### Answer:
$$
\boxed{\text{Bus}}
$$

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Graph 3: Pie Chart

#### Description:
- The pie chart shows the percentage distribution of energy sources used in a country.
- The chart is divided into four segments, each labeled with an energy source and its corresponding percentage:
- Fossil fuels: 60%
- Renewable energy: 25%
- Nuclear energy: 10%
- Other: 5%

#### Question:
> What percentage of the total energy comes from renewable energy sources?

#### Solution:
1. Identify the segment labeled "Renewable energy" in the pie chart.
2. Read the percentage associated with this segment.
3. From the chart, the percentage for renewable energy is 25%.

#### Answer:
$$
\boxed{25\%}
$$

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Final Answers:

1. Line Graph: The approximate growth rate of bacteria at hour 3 is $\boxed{75\%}$.
2. Bar Graph: The mode of transportation preferred by the most students is $\boxed{\text{Bus}}$.
3. Pie Chart: The percentage of the total energy that comes from renewable energy sources is $\boxed{25\%}$.