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Finding the Fourth Proportional to 486.45, 729.80 and 280.65

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Solution

The fourth proportional to 486.45, 729.80 and 280.65 is: 421.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.45 : 729.80 = 280.65 : x
  2. Step 2: Convert to fraction form
    486.45/729.80 = 280.65/x
  3. Step 3: Cross multiply
    486.45x = 729.80 × 280.65
  4. Step 4: Simplify right side
    486.45x = 204,818.37
  5. Step 5: Solve for x
    x = 204,818.37/486.45
  6. Step 6: Final answer
    x = 421.05

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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.