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Finding the Fourth Proportional to 390.72, 586.32 and 339.75

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Solution

The fourth proportional to 390.72, 586.32 and 339.75 is: 509.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.72 : 586.32 = 339.75 : x
  2. Step 2: Convert to fraction form
    390.72/586.32 = 339.75/x
  3. Step 3: Cross multiply
    390.72x = 586.32 × 339.75
  4. Step 4: Simplify right side
    390.72x = 199,202.22
  5. Step 5: Solve for x
    x = 199,202.22/390.72
  6. Step 6: Final answer
    x = 509.83

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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.