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Finding the Fourth Proportional to 787.18, 1,085.85 and 491.94

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Solution

The fourth proportional to 787.18, 1,085.85 and 491.94 is: 678.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.18 : 1,085.85 = 491.94 : x
  2. Step 2: Convert to fraction form
    787.18/1,085.85 = 491.94/x
  3. Step 3: Cross multiply
    787.18x = 1,085.85 × 491.94
  4. Step 4: Simplify right side
    787.18x = 534,173.05
  5. Step 5: Solve for x
    x = 534,173.05/787.18
  6. Step 6: Final answer
    x = 678.59

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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.