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Finding the Fourth Proportional to 505.91, 698.21 and 309.55

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Solution

The fourth proportional to 505.91, 698.21 and 309.55 is: 427.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.91 : 698.21 = 309.55 : x
  2. Step 2: Convert to fraction form
    505.91/698.21 = 309.55/x
  3. Step 3: Cross multiply
    505.91x = 698.21 × 309.55
  4. Step 4: Simplify right side
    505.91x = 216,129.36
  5. Step 5: Solve for x
    x = 216,129.36/505.91
  6. Step 6: Final answer
    x = 427.21

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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.