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Finding the Fourth Proportional to 686.56, 1,030.16 and 320.90

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Solution

The fourth proportional to 686.56, 1,030.16 and 320.90 is: 481.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.56 : 1,030.16 = 320.90 : x
  2. Step 2: Convert to fraction form
    686.56/1,030.16 = 320.90/x
  3. Step 3: Cross multiply
    686.56x = 1,030.16 × 320.90
  4. Step 4: Simplify right side
    686.56x = 330,578.34
  5. Step 5: Solve for x
    x = 330,578.34/686.56
  6. Step 6: Final answer
    x = 481.50

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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.