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Finding the Fourth Proportional to 685.57, 946.21 and 662.80

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Solution

The fourth proportional to 685.57, 946.21 and 662.80 is: 914.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.57 : 946.21 = 662.80 : x
  2. Step 2: Convert to fraction form
    685.57/946.21 = 662.80/x
  3. Step 3: Cross multiply
    685.57x = 946.21 × 662.80
  4. Step 4: Simplify right side
    685.57x = 627,147.99
  5. Step 5: Solve for x
    x = 627,147.99/685.57
  6. Step 6: Final answer
    x = 914.78

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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.