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Finding the Fourth Proportional to 609.19, 840.81 and 388.09

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Solution

The fourth proportional to 609.19, 840.81 and 388.09 is: 535.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    609.19 : 840.81 = 388.09 : x
  2. Step 2: Convert to fraction form
    609.19/840.81 = 388.09/x
  3. Step 3: Cross multiply
    609.19x = 840.81 × 388.09
  4. Step 4: Simplify right side
    609.19x = 326,307.85
  5. Step 5: Solve for x
    x = 326,307.85/609.19
  6. Step 6: Final answer
    x = 535.64

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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.