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Finding the Fourth Proportional to 686.02, 1,028.70 and 412.64

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Solution

The fourth proportional to 686.02, 1,028.70 and 412.64 is: 618.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.02 : 1,028.70 = 412.64 : x
  2. Step 2: Convert to fraction form
    686.02/1,028.70 = 412.64/x
  3. Step 3: Cross multiply
    686.02x = 1,028.70 × 412.64
  4. Step 4: Simplify right side
    686.02x = 424,482.77
  5. Step 5: Solve for x
    x = 424,482.77/686.02
  6. Step 6: Final answer
    x = 618.76

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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.