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Finding the Fourth Proportional to 821.22, 1,230.63 and 430.37

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Solution

The fourth proportional to 821.22, 1,230.63 and 430.37 is: 644.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.22 : 1,230.63 = 430.37 : x
  2. Step 2: Convert to fraction form
    821.22/1,230.63 = 430.37/x
  3. Step 3: Cross multiply
    821.22x = 1,230.63 × 430.37
  4. Step 4: Simplify right side
    821.22x = 529,620.08
  5. Step 5: Solve for x
    x = 529,620.08/821.22
  6. Step 6: Final answer
    x = 644.92

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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.