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Finding the Fourth Proportional to 686.79, 1,030.23 and 321.68

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Solution

The fourth proportional to 686.79, 1,030.23 and 321.68 is: 482.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.79 : 1,030.23 = 321.68 : x
  2. Step 2: Convert to fraction form
    686.79/1,030.23 = 321.68/x
  3. Step 3: Cross multiply
    686.79x = 1,030.23 × 321.68
  4. Step 4: Simplify right side
    686.79x = 331,406.96
  5. Step 5: Solve for x
    x = 331,406.96/686.79
  6. Step 6: Final answer
    x = 482.54

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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.