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Finding the Fourth Proportional to 386.60, 579.91 and 126.60

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Solution

The fourth proportional to 386.60, 579.91 and 126.60 is: 189.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.60 : 579.91 = 126.60 : x
  2. Step 2: Convert to fraction form
    386.60/579.91 = 126.60/x
  3. Step 3: Cross multiply
    386.60x = 579.91 × 126.60
  4. Step 4: Simplify right side
    386.60x = 73,416.61
  5. Step 5: Solve for x
    x = 73,416.61/386.60
  6. Step 6: Final answer
    x = 189.90

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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.