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Finding the Fourth Proportional to 863.80, 1,191.81 and 490.79

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Solution

The fourth proportional to 863.80, 1,191.81 and 490.79 is: 677.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    863.80 : 1,191.81 = 490.79 : x
  2. Step 2: Convert to fraction form
    863.80/1,191.81 = 490.79/x
  3. Step 3: Cross multiply
    863.80x = 1,191.81 × 490.79
  4. Step 4: Simplify right side
    863.80x = 584,933.25
  5. Step 5: Solve for x
    x = 584,933.25/863.80
  6. Step 6: Final answer
    x = 677.16

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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.