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Finding the Fourth Proportional to 820.64, 1,229.49 and 430.07

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Solution

The fourth proportional to 820.64, 1,229.49 and 430.07 is: 644.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.64 : 1,229.49 = 430.07 : x
  2. Step 2: Convert to fraction form
    820.64/1,229.49 = 430.07/x
  3. Step 3: Cross multiply
    820.64x = 1,229.49 × 430.07
  4. Step 4: Simplify right side
    820.64x = 528,760.62
  5. Step 5: Solve for x
    x = 528,760.62/820.64
  6. Step 6: Final answer
    x = 644.33

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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.