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Finding the Fourth Proportional to 665.80, 919.38 and 417.55

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Solution

The fourth proportional to 665.80, 919.38 and 417.55 is: 576.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.80 : 919.38 = 417.55 : x
  2. Step 2: Convert to fraction form
    665.80/919.38 = 417.55/x
  3. Step 3: Cross multiply
    665.80x = 919.38 × 417.55
  4. Step 4: Simplify right side
    665.80x = 383,884.82
  5. Step 5: Solve for x
    x = 383,884.82/665.80
  6. Step 6: Final answer
    x = 576.58

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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.