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Finding the Fourth Proportional to 386.62, 579.93 and 139.83

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Solution

The fourth proportional to 386.62, 579.93 and 139.83 is: 209.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.62 : 579.93 = 139.83 : x
  2. Step 2: Convert to fraction form
    386.62/579.93 = 139.83/x
  3. Step 3: Cross multiply
    386.62x = 579.93 × 139.83
  4. Step 4: Simplify right side
    386.62x = 81,088.91
  5. Step 5: Solve for x
    x = 81,088.91/386.62
  6. Step 6: Final answer
    x = 209.74

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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.