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Finding the Fourth Proportional to 390.24, 585.05 and 338.76

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Solution

The fourth proportional to 390.24, 585.05 and 338.76 is: 507.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.24 : 585.05 = 338.76 : x
  2. Step 2: Convert to fraction form
    390.24/585.05 = 338.76/x
  3. Step 3: Cross multiply
    390.24x = 585.05 × 338.76
  4. Step 4: Simplify right side
    390.24x = 198,189.84
  5. Step 5: Solve for x
    x = 198,189.84/390.24
  6. Step 6: Final answer
    x = 507.87

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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.