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Finding the Fourth Proportional to 685.56, 946.10 and 405.80

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Solution

The fourth proportional to 685.56, 946.10 and 405.80 is: 560.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.56 : 946.10 = 405.80 : x
  2. Step 2: Convert to fraction form
    685.56/946.10 = 405.80/x
  3. Step 3: Cross multiply
    685.56x = 946.10 × 405.80
  4. Step 4: Simplify right side
    685.56x = 383,927.38
  5. Step 5: Solve for x
    x = 383,927.38/685.56
  6. Step 6: Final answer
    x = 560.02

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1.5x scale

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.