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Finding the Fourth Proportional to 685.55, 946.06 and 405.80

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Solution

The fourth proportional to 685.55, 946.06 and 405.80 is: 560.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.55 : 946.06 = 405.80 : x
  2. Step 2: Convert to fraction form
    685.55/946.06 = 405.80/x
  3. Step 3: Cross multiply
    685.55x = 946.06 × 405.80
  4. Step 4: Simplify right side
    685.55x = 383,905.40
  5. Step 5: Solve for x
    x = 383,905.40/685.55
  6. Step 6: Final answer
    x = 560.00

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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.