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Finding the Fourth Proportional to 505.72, 697.96 and 309.28

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Solution

The fourth proportional to 505.72, 697.96 and 309.28 is: 426.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.72 : 697.96 = 309.28 : x
  2. Step 2: Convert to fraction form
    505.72/697.96 = 309.28/x
  3. Step 3: Cross multiply
    505.72x = 697.96 × 309.28
  4. Step 4: Simplify right side
    505.72x = 215,865.07
  5. Step 5: Solve for x
    x = 215,865.07/505.72
  6. Step 6: Final answer
    x = 426.85

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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.