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Finding the Fourth Proportional to 491.72, 678.56 and 281.94

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Solution

The fourth proportional to 491.72, 678.56 and 281.94 is: 389.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.72 : 678.56 = 281.94 : x
  2. Step 2: Convert to fraction form
    491.72/678.56 = 281.94/x
  3. Step 3: Cross multiply
    491.72x = 678.56 × 281.94
  4. Step 4: Simplify right side
    491.72x = 191,313.21
  5. Step 5: Solve for x
    x = 191,313.21/491.72
  6. Step 6: Final answer
    x = 389.07

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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.