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Finding the Fourth Proportional to 820.21, 1,232.62 and 491.20

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Solution

The fourth proportional to 820.21, 1,232.62 and 491.20 is: 738.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.21 : 1,232.62 = 491.20 : x
  2. Step 2: Convert to fraction form
    820.21/1,232.62 = 491.20/x
  3. Step 3: Cross multiply
    820.21x = 1,232.62 × 491.20
  4. Step 4: Simplify right side
    820.21x = 605,462.94
  5. Step 5: Solve for x
    x = 605,462.94/820.21
  6. Step 6: Final answer
    x = 738.18

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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.