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Finding the Fourth Proportional to 821.01, 1,131.93 and 489.30

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Solution

The fourth proportional to 821.01, 1,131.93 and 489.30 is: 674.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.01 : 1,131.93 = 489.30 : x
  2. Step 2: Convert to fraction form
    821.01/1,131.93 = 489.30/x
  3. Step 3: Cross multiply
    821.01x = 1,131.93 × 489.30
  4. Step 4: Simplify right side
    821.01x = 553,853.35
  5. Step 5: Solve for x
    x = 553,853.35/821.01
  6. Step 6: Final answer
    x = 674.60

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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.