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Finding the Fourth Proportional to 802.78, 1,202.28 and 392.20

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Solution

The fourth proportional to 802.78, 1,202.28 and 392.20 is: 587.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    802.78 : 1,202.28 = 392.20 : x
  2. Step 2: Convert to fraction form
    802.78/1,202.28 = 392.20/x
  3. Step 3: Cross multiply
    802.78x = 1,202.28 × 392.20
  4. Step 4: Simplify right side
    802.78x = 471,534.22
  5. Step 5: Solve for x
    x = 471,534.22/802.78
  6. Step 6: Final answer
    x = 587.38

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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.