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Finding the Fourth Proportional to 863.20, 1,191.21 and 490.15

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Solution

The fourth proportional to 863.20, 1,191.21 and 490.15 is: 676.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    863.20 : 1,191.21 = 490.15 : x
  2. Step 2: Convert to fraction form
    863.20/1,191.21 = 490.15/x
  3. Step 3: Cross multiply
    863.20x = 1,191.21 × 490.15
  4. Step 4: Simplify right side
    863.20x = 583,871.58
  5. Step 5: Solve for x
    x = 583,871.58/863.20
  6. Step 6: Final answer
    x = 676.40

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.