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Finding the Fourth Proportional to 428.92, 642.20 and 324.50

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Solution

The fourth proportional to 428.92, 642.20 and 324.50 is: 485.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.92 : 642.20 = 324.50 : x
  2. Step 2: Convert to fraction form
    428.92/642.20 = 324.50/x
  3. Step 3: Cross multiply
    428.92x = 642.20 × 324.50
  4. Step 4: Simplify right side
    428.92x = 208,389.07
  5. Step 5: Solve for x
    x = 208,389.07/428.92
  6. Step 6: Final answer
    x = 485.85

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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.