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Finding the Fourth Proportional to 505.55, 697.68 and 309

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Solution

The fourth proportional to 505.55, 697.68 and 309 is: 426.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.55 : 697.68 = 309 : x
  2. Step 2: Convert to fraction form
    505.55/697.68 = 309/x
  3. Step 3: Cross multiply
    505.55x = 697.68 × 309
  4. Step 4: Simplify right side
    505.55x = 215,583.12
  5. Step 5: Solve for x
    x = 215,583.12/505.55
  6. Step 6: Final answer
    x = 426.44

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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.