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Finding the Fourth Proportional to 1,285.86, 1,773.42 and 787.70

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Solution

The fourth proportional to 1,285.86, 1,773.42 and 787.70 is: 1,086.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,285.86 : 1,773.42 = 787.70 : x
  2. Step 2: Convert to fraction form
    1,285.86/1,773.42 = 787.70/x
  3. Step 3: Cross multiply
    1,285.86x = 1,773.42 × 787.70
  4. Step 4: Simplify right side
    1,285.86x = 1,396,922.93
  5. Step 5: Solve for x
    x = 1,396,922.93/1,285.86
  6. Step 6: Final answer
    x = 1,086.37

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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.