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Finding the Fourth Proportional to 619.80, 855.72 and 488.40

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Solution

The fourth proportional to 619.80, 855.72 and 488.40 is: 674.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.80 : 855.72 = 488.40 : x
  2. Step 2: Convert to fraction form
    619.80/855.72 = 488.40/x
  3. Step 3: Cross multiply
    619.80x = 855.72 × 488.40
  4. Step 4: Simplify right side
    619.80x = 417,933.65
  5. Step 5: Solve for x
    x = 417,933.65/619.80
  6. Step 6: Final answer
    x = 674.30

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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.