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Finding the Fourth Proportional to 390.88, 539.45 and 308.62

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Solution

The fourth proportional to 390.88, 539.45 and 308.62 is: 425.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.88 : 539.45 = 308.62 : x
  2. Step 2: Convert to fraction form
    390.88/539.45 = 308.62/x
  3. Step 3: Cross multiply
    390.88x = 539.45 × 308.62
  4. Step 4: Simplify right side
    390.88x = 166,485.06
  5. Step 5: Solve for x
    x = 166,485.06/390.88
  6. Step 6: Final answer
    x = 425.92

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.