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Finding the Fourth Proportional to 505.89, 698.47 and 387.65

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Solution

The fourth proportional to 505.89, 698.47 and 387.65 is: 535.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.89 : 698.47 = 387.65 : x
  2. Step 2: Convert to fraction form
    505.89/698.47 = 387.65/x
  3. Step 3: Cross multiply
    505.89x = 698.47 × 387.65
  4. Step 4: Simplify right side
    505.89x = 270,759.96
  5. Step 5: Solve for x
    x = 270,759.96/505.89
  6. Step 6: Final answer
    x = 535.22

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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.