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Finding the Fourth Proportional to 820.81, 1,132.46 and 489.34

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Solution

The fourth proportional to 820.81, 1,132.46 and 489.34 is: 675.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.81 : 1,132.46 = 489.34 : x
  2. Step 2: Convert to fraction form
    820.81/1,132.46 = 489.34/x
  3. Step 3: Cross multiply
    820.81x = 1,132.46 × 489.34
  4. Step 4: Simplify right side
    820.81x = 554,157.40
  5. Step 5: Solve for x
    x = 554,157.40/820.81
  6. Step 6: Final answer
    x = 675.14

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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.