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Finding the Fourth Proportional to 386.60, 579.90 and 338.60

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Solution

The fourth proportional to 386.60, 579.90 and 338.60 is: 507.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.60 : 579.90 = 338.60 : x
  2. Step 2: Convert to fraction form
    386.60/579.90 = 338.60/x
  3. Step 3: Cross multiply
    386.60x = 579.90 × 338.60
  4. Step 4: Simplify right side
    386.60x = 196,354.14
  5. Step 5: Solve for x
    x = 196,354.14/386.60
  6. Step 6: Final answer
    x = 507.90

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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.