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Finding the Fourth Proportional to 786.20, 1,178.78 and 439.57

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Solution

The fourth proportional to 786.20, 1,178.78 and 439.57 is: 659.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    786.20 : 1,178.78 = 439.57 : x
  2. Step 2: Convert to fraction form
    786.20/1,178.78 = 439.57/x
  3. Step 3: Cross multiply
    786.20x = 1,178.78 × 439.57
  4. Step 4: Simplify right side
    786.20x = 518,153.38
  5. Step 5: Solve for x
    x = 518,153.38/786.20
  6. Step 6: Final answer
    x = 659.06

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1.5x scale

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.