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Finding the Fourth Proportional to 919.15, 1,379.03 and 486

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Solution

The fourth proportional to 919.15, 1,379.03 and 486 is: 729.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    919.15 : 1,379.03 = 486 : x
  2. Step 2: Convert to fraction form
    919.15/1,379.03 = 486/x
  3. Step 3: Cross multiply
    919.15x = 1,379.03 × 486
  4. Step 4: Simplify right side
    919.15x = 670,206.15
  5. Step 5: Solve for x
    x = 670,206.15/919.15
  6. Step 6: Final answer
    x = 729.16

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.