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Finding the Fourth Proportional to 505.98, 698.20 and 309.45

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Solution

The fourth proportional to 505.98, 698.20 and 309.45 is: 427.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.98 : 698.20 = 309.45 : x
  2. Step 2: Convert to fraction form
    505.98/698.20 = 309.45/x
  3. Step 3: Cross multiply
    505.98x = 698.20 × 309.45
  4. Step 4: Simplify right side
    505.98x = 216,057.99
  5. Step 5: Solve for x
    x = 216,057.99/505.98
  6. Step 6: Final answer
    x = 427.01

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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.