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Finding the Fourth Proportional to 686.89, 1,030.35 and 321.58

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Solution

The fourth proportional to 686.89, 1,030.35 and 321.58 is: 482.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.89 : 1,030.35 = 321.58 : x
  2. Step 2: Convert to fraction form
    686.89/1,030.35 = 321.58/x
  3. Step 3: Cross multiply
    686.89x = 1,030.35 × 321.58
  4. Step 4: Simplify right side
    686.89x = 331,339.95
  5. Step 5: Solve for x
    x = 331,339.95/686.89
  6. Step 6: Final answer
    x = 482.38

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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.