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Finding the Fourth Proportional to 679.93, 1,018.27 and 390.49

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Solution

The fourth proportional to 679.93, 1,018.27 and 390.49 is: 584.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.93 : 1,018.27 = 390.49 : x
  2. Step 2: Convert to fraction form
    679.93/1,018.27 = 390.49/x
  3. Step 3: Cross multiply
    679.93x = 1,018.27 × 390.49
  4. Step 4: Simplify right side
    679.93x = 397,624.25
  5. Step 5: Solve for x
    x = 397,624.25/679.93
  6. Step 6: Final answer
    x = 584.80

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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.