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Finding the Fourth Proportional to 679.60, 1,018.14 and 390.16

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Solution

The fourth proportional to 679.60, 1,018.14 and 390.16 is: 584.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.60 : 1,018.14 = 390.16 : x
  2. Step 2: Convert to fraction form
    679.60/1,018.14 = 390.16/x
  3. Step 3: Cross multiply
    679.60x = 1,018.14 × 390.16
  4. Step 4: Simplify right side
    679.60x = 397,237.50
  5. Step 5: Solve for x
    x = 397,237.50/679.60
  6. Step 6: Final answer
    x = 584.52

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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.