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Finding the Fourth Proportional to 685.58, 1,028.63 and 411.86

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Solution

The fourth proportional to 685.58, 1,028.63 and 411.86 is: 617.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.58 : 1,028.63 = 411.86 : x
  2. Step 2: Convert to fraction form
    685.58/1,028.63 = 411.86/x
  3. Step 3: Cross multiply
    685.58x = 1,028.63 × 411.86
  4. Step 4: Simplify right side
    685.58x = 423,655.15
  5. Step 5: Solve for x
    x = 423,655.15/685.58
  6. Step 6: Final answer
    x = 617.96

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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.