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Finding the Fourth Proportional to 491.56, 678.47 and 281.86

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Solution

The fourth proportional to 491.56, 678.47 and 281.86 is: 389.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.56 : 678.47 = 281.86 : x
  2. Step 2: Convert to fraction form
    491.56/678.47 = 281.86/x
  3. Step 3: Cross multiply
    491.56x = 678.47 × 281.86
  4. Step 4: Simplify right side
    491.56x = 191,230.45
  5. Step 5: Solve for x
    x = 191,230.45/491.56
  6. Step 6: Final answer
    x = 389.03

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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.