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Finding the Fourth Proportional to 685.53, 946.07 and 405.72

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Solution

The fourth proportional to 685.53, 946.07 and 405.72 is: 559.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.53 : 946.07 = 405.72 : x
  2. Step 2: Convert to fraction form
    685.53/946.07 = 405.72/x
  3. Step 3: Cross multiply
    685.53x = 946.07 × 405.72
  4. Step 4: Simplify right side
    685.53x = 383,839.01
  5. Step 5: Solve for x
    x = 383,839.01/685.53
  6. Step 6: Final answer
    x = 559.92

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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.