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Finding the Fourth Proportional to 860.81, 1,291.32 and 398.52

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Solution

The fourth proportional to 860.81, 1,291.32 and 398.52 is: 597.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.81 : 1,291.32 = 398.52 : x
  2. Step 2: Convert to fraction form
    860.81/1,291.32 = 398.52/x
  3. Step 3: Cross multiply
    860.81x = 1,291.32 × 398.52
  4. Step 4: Simplify right side
    860.81x = 514,616.85
  5. Step 5: Solve for x
    x = 514,616.85/860.81
  6. Step 6: Final answer
    x = 597.83

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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.