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Finding the Fourth Proportional to 863.80, 1,191.78 and 490.78

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Solution

The fourth proportional to 863.80, 1,191.78 and 490.78 is: 677.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    863.80 : 1,191.78 = 490.78 : x
  2. Step 2: Convert to fraction form
    863.80/1,191.78 = 490.78/x
  3. Step 3: Cross multiply
    863.80x = 1,191.78 × 490.78
  4. Step 4: Simplify right side
    863.80x = 584,901.79
  5. Step 5: Solve for x
    x = 584,901.79/863.80
  6. Step 6: Final answer
    x = 677.13

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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.