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Finding the Fourth Proportional to 787.32, 1,086.19 and 492.78

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Solution

The fourth proportional to 787.32, 1,086.19 and 492.78 is: 679.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.32 : 1,086.19 = 492.78 : x
  2. Step 2: Convert to fraction form
    787.32/1,086.19 = 492.78/x
  3. Step 3: Cross multiply
    787.32x = 1,086.19 × 492.78
  4. Step 4: Simplify right side
    787.32x = 535,255.55
  5. Step 5: Solve for x
    x = 535,255.55/787.32
  6. Step 6: Final answer
    x = 679.84

Related Problems

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Half scale
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Double scale
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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.