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Finding the Fourth Proportional to 390.39, 585.81 and 303.90

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Solution

The fourth proportional to 390.39, 585.81 and 303.90 is: 456.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.39 : 585.81 = 303.90 : x
  2. Step 2: Convert to fraction form
    390.39/585.81 = 303.90/x
  3. Step 3: Cross multiply
    390.39x = 585.81 × 303.90
  4. Step 4: Simplify right side
    390.39x = 178,027.90
  5. Step 5: Solve for x
    x = 178,027.90/390.39
  6. Step 6: Final answer
    x = 456.02

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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.