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Finding the Fourth Proportional to 801.60, 1,201.62 and 390.81

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Solution

The fourth proportional to 801.60, 1,201.62 and 390.81 is: 585.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    801.60 : 1,201.62 = 390.81 : x
  2. Step 2: Convert to fraction form
    801.60/1,201.62 = 390.81/x
  3. Step 3: Cross multiply
    801.60x = 1,201.62 × 390.81
  4. Step 4: Simplify right side
    801.60x = 469,605.11
  5. Step 5: Solve for x
    x = 469,605.11/801.60
  6. Step 6: Final answer
    x = 585.83

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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.