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Finding the Fourth Proportional to 920.72, 1,381.30 and 509.76

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Solution

The fourth proportional to 920.72, 1,381.30 and 509.76 is: 764.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.72 : 1,381.30 = 509.76 : x
  2. Step 2: Convert to fraction form
    920.72/1,381.30 = 509.76/x
  3. Step 3: Cross multiply
    920.72x = 1,381.30 × 509.76
  4. Step 4: Simplify right side
    920.72x = 704,130.21
  5. Step 5: Solve for x
    x = 704,130.21/920.72
  6. Step 6: Final answer
    x = 764.76

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.