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Finding the Fourth Proportional to 610.85, 843.09 and 390.05

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Solution

The fourth proportional to 610.85, 843.09 and 390.05 is: 538.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    610.85 : 843.09 = 390.05 : x
  2. Step 2: Convert to fraction form
    610.85/843.09 = 390.05/x
  3. Step 3: Cross multiply
    610.85x = 843.09 × 390.05
  4. Step 4: Simplify right side
    610.85x = 328,847.25
  5. Step 5: Solve for x
    x = 328,847.25/610.85
  6. Step 6: Final answer
    x = 538.34

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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.