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Finding the Fourth Proportional to 801.85, 1,201.56 and 390.79

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Solution

The fourth proportional to 801.85, 1,201.56 and 390.79 is: 585.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    801.85 : 1,201.56 = 390.79 : x
  2. Step 2: Convert to fraction form
    801.85/1,201.56 = 390.79/x
  3. Step 3: Cross multiply
    801.85x = 1,201.56 × 390.79
  4. Step 4: Simplify right side
    801.85x = 469,557.63
  5. Step 5: Solve for x
    x = 469,557.63/801.85
  6. Step 6: Final answer
    x = 585.59

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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.