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Finding the Fourth Proportional to 862.81, 1,190.71 and 489.81

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Solution

The fourth proportional to 862.81, 1,190.71 and 489.81 is: 675.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    862.81 : 1,190.71 = 489.81 : x
  2. Step 2: Convert to fraction form
    862.81/1,190.71 = 489.81/x
  3. Step 3: Cross multiply
    862.81x = 1,190.71 × 489.81
  4. Step 4: Simplify right side
    862.81x = 583,217.29
  5. Step 5: Solve for x
    x = 583,217.29/862.81
  6. Step 6: Final answer
    x = 675.95

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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.