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Finding the Fourth Proportional to 822.21, 1,232.91 and 389.40

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Solution

The fourth proportional to 822.21, 1,232.91 and 389.40 is: 583.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    822.21 : 1,232.91 = 389.40 : x
  2. Step 2: Convert to fraction form
    822.21/1,232.91 = 389.40/x
  3. Step 3: Cross multiply
    822.21x = 1,232.91 × 389.40
  4. Step 4: Simplify right side
    822.21x = 480,095.15
  5. Step 5: Solve for x
    x = 480,095.15/822.21
  6. Step 6: Final answer
    x = 583.91

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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.