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Finding the Fourth Proportional to 421.51, 581.79 and 281.86

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Solution

The fourth proportional to 421.51, 581.79 and 281.86 is: 389.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.51 : 581.79 = 281.86 : x
  2. Step 2: Convert to fraction form
    421.51/581.79 = 281.86/x
  3. Step 3: Cross multiply
    421.51x = 581.79 × 281.86
  4. Step 4: Simplify right side
    421.51x = 163,983.33
  5. Step 5: Solve for x
    x = 163,983.33/421.51
  6. Step 6: Final answer
    x = 389.04

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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.