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Finding the Fourth Proportional to 820.28, 1,230.50 and 387.32

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Solution

The fourth proportional to 820.28, 1,230.50 and 387.32 is: 581.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.28 : 1,230.50 = 387.32 : x
  2. Step 2: Convert to fraction form
    820.28/1,230.50 = 387.32/x
  3. Step 3: Cross multiply
    820.28x = 1,230.50 × 387.32
  4. Step 4: Simplify right side
    820.28x = 476,597.26
  5. Step 5: Solve for x
    x = 476,597.26/820.28
  6. Step 6: Final answer
    x = 581.02

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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.