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Finding the Fourth Proportional to 656.52, 905.69 and 390.81

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Solution

The fourth proportional to 656.52, 905.69 and 390.81 is: 539.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.52 : 905.69 = 390.81 : x
  2. Step 2: Convert to fraction form
    656.52/905.69 = 390.81/x
  3. Step 3: Cross multiply
    656.52x = 905.69 × 390.81
  4. Step 4: Simplify right side
    656.52x = 353,950.75
  5. Step 5: Solve for x
    x = 353,950.75/656.52
  6. Step 6: Final answer
    x = 539.13

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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.