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Finding the Fourth Proportional to 386.37, 579.64 and 139.59

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Solution

The fourth proportional to 386.37, 579.64 and 139.59 is: 209.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.37 : 579.64 = 139.59 : x
  2. Step 2: Convert to fraction form
    386.37/579.64 = 139.59/x
  3. Step 3: Cross multiply
    386.37x = 579.64 × 139.59
  4. Step 4: Simplify right side
    386.37x = 80,911.95
  5. Step 5: Solve for x
    x = 80,911.95/386.37
  6. Step 6: Final answer
    x = 209.42

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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.