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Finding the Fourth Proportional to 787.11, 1,086.42 and 492.21

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Solution

The fourth proportional to 787.11, 1,086.42 and 492.21 is: 679.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.11 : 1,086.42 = 492.21 : x
  2. Step 2: Convert to fraction form
    787.11/1,086.42 = 492.21/x
  3. Step 3: Cross multiply
    787.11x = 1,086.42 × 492.21
  4. Step 4: Simplify right side
    787.11x = 534,746.79
  5. Step 5: Solve for x
    x = 534,746.79/787.11
  6. Step 6: Final answer
    x = 679.38

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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.