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Finding the Fourth Proportional to 781.80, 1,173.28 and 489.74

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Solution

The fourth proportional to 781.80, 1,173.28 and 489.74 is: 734.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.80 : 1,173.28 = 489.74 : x
  2. Step 2: Convert to fraction form
    781.80/1,173.28 = 489.74/x
  3. Step 3: Cross multiply
    781.80x = 1,173.28 × 489.74
  4. Step 4: Simplify right side
    781.80x = 574,602.15
  5. Step 5: Solve for x
    x = 574,602.15/781.80
  6. Step 6: Final answer
    x = 734.97

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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.