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Finding the Fourth Proportional to 820.70, 1,132.51 and 489.15

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Solution

The fourth proportional to 820.70, 1,132.51 and 489.15 is: 674.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.70 : 1,132.51 = 489.15 : x
  2. Step 2: Convert to fraction form
    820.70/1,132.51 = 489.15/x
  3. Step 3: Cross multiply
    820.70x = 1,132.51 × 489.15
  4. Step 4: Simplify right side
    820.70x = 553,967.27
  5. Step 5: Solve for x
    x = 553,967.27/820.70
  6. Step 6: Final answer
    x = 674.99

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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.