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Finding the Fourth Proportional to 430.82, 642.75 and 391.85

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Solution

The fourth proportional to 430.82, 642.75 and 391.85 is: 584.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.82 : 642.75 = 391.85 : x
  2. Step 2: Convert to fraction form
    430.82/642.75 = 391.85/x
  3. Step 3: Cross multiply
    430.82x = 642.75 × 391.85
  4. Step 4: Simplify right side
    430.82x = 251,858.37
  5. Step 5: Solve for x
    x = 251,858.37/430.82
  6. Step 6: Final answer
    x = 584.61

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.