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Finding the Fourth Proportional to 610.40, 840.49 and 485.66

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Solution

The fourth proportional to 610.40, 840.49 and 485.66 is: 668.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    610.40 : 840.49 = 485.66 : x
  2. Step 2: Convert to fraction form
    610.40/840.49 = 485.66/x
  3. Step 3: Cross multiply
    610.40x = 840.49 × 485.66
  4. Step 4: Simplify right side
    610.40x = 408,186.96
  5. Step 5: Solve for x
    x = 408,186.96/610.40
  6. Step 6: Final answer
    x = 668.73

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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.