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Finding the Fourth Proportional to 863.70, 1,191.80 and 490.70

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Solution

The fourth proportional to 863.70, 1,191.80 and 490.70 is: 677.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    863.70 : 1,191.80 = 490.70 : x
  2. Step 2: Convert to fraction form
    863.70/1,191.80 = 490.70/x
  3. Step 3: Cross multiply
    863.70x = 1,191.80 × 490.70
  4. Step 4: Simplify right side
    863.70x = 584,816.26
  5. Step 5: Solve for x
    x = 584,816.26/863.70
  6. Step 6: Final answer
    x = 677.11

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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.