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Finding the Fourth Proportional to 421.86, 581.87 and 281.91

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Solution

The fourth proportional to 421.86, 581.87 and 281.91 is: 388.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.86 : 581.87 = 281.91 : x
  2. Step 2: Convert to fraction form
    421.86/581.87 = 281.91/x
  3. Step 3: Cross multiply
    421.86x = 581.87 × 281.91
  4. Step 4: Simplify right side
    421.86x = 164,034.97
  5. Step 5: Solve for x
    x = 164,034.97/421.86
  6. Step 6: Final answer
    x = 388.84

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.