- The initial expression to calculate is \((3000 \div 30000) \times 100\).
- Simplify the fraction \(\frac{3000}{30000}\) to \(0.1\).
- Multiply the decimal \(0.1\) by \(100\) to find the percentage: \(10\%\).
- The final answer is \(\boxed{10\%}\).
Explanation
- Problem Analysis
The problem asks us to determine the percentage of energy transferred from the bottom level of an energy pyramid to the level occupied by oak leaves, given by the expression \((3000 \div 30000) \times 100\). An energy pyramid represents the flow of energy through a food chain, and calculating this percentage helps us understand how efficiently energy is passed between trophic levels. We are given four options: \(100\%\), \(1000\%\), \(50\%\), and \(10\%\).
- Calculations
To solve the expression \((3000 \div 30000) \times 100\), we first perform the division inside the parentheses. Dividing \(3000\) by \(30000\) simplifies as follows:
\[ \frac{3000}{30000} = \frac{3}{30} = \frac{1}{10} = 0.1 \]
Next, we convert this decimal to a percentage by multiplying it by \(100\):
\[ 0.1 \times 100 = 10 \]
Therefore, the result is \(10\%\). Comparing this to our options, we find that it matches the option \(10\%\).
Examples
In ecology, energy pyramids illustrate how energy decreases as it moves up trophic levels. For example, if a primary producer level (like grass) has \(30,000\) units of energy and the primary consumer level (like caterpillars eating oak leaves) has \(3,000\) units, the efficiency of energy transfer can be calculated as \(\frac{3,000}{30,000} \times 100 = 10\%\). This is a practical way to assess how much energy is successfully converted into biomass by organisms at each stage of a food chain.