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Finding the Fourth Proportional to 639.36, 882.48 and 418.80

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Solution

The fourth proportional to 639.36, 882.48 and 418.80 is: 578.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.36 : 882.48 = 418.80 : x
  2. Step 2: Convert to fraction form
    639.36/882.48 = 418.80/x
  3. Step 3: Cross multiply
    639.36x = 882.48 × 418.80
  4. Step 4: Simplify right side
    639.36x = 369,582.62
  5. Step 5: Solve for x
    x = 369,582.62/639.36
  6. Step 6: Final answer
    x = 578.05

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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.