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Finding the Fourth Proportional to 428.46, 642.62 and 120.36

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Solution

The fourth proportional to 428.46, 642.62 and 120.36 is: 180.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.46 : 642.62 = 120.36 : x
  2. Step 2: Convert to fraction form
    428.46/642.62 = 120.36/x
  3. Step 3: Cross multiply
    428.46x = 642.62 × 120.36
  4. Step 4: Simplify right side
    428.46x = 77,345.74
  5. Step 5: Solve for x
    x = 77,345.74/428.46
  6. Step 6: Final answer
    x = 180.52

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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.