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Finding the Fourth Proportional to 896.78, 1,345.21 and 280.50

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Solution

The fourth proportional to 896.78, 1,345.21 and 280.50 is: 420.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    896.78 : 1,345.21 = 280.50 : x
  2. Step 2: Convert to fraction form
    896.78/1,345.21 = 280.50/x
  3. Step 3: Cross multiply
    896.78x = 1,345.21 × 280.50
  4. Step 4: Simplify right side
    896.78x = 377,324.68
  5. Step 5: Solve for x
    x = 377,324.68/896.78
  6. Step 6: Final answer
    x = 420.76

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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.