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Finding the Fourth Proportional to 491.54, 678.36 and 281.72

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Solution

The fourth proportional to 491.54, 678.36 and 281.72 is: 388.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.54 : 678.36 = 281.72 : x
  2. Step 2: Convert to fraction form
    491.54/678.36 = 281.72/x
  3. Step 3: Cross multiply
    491.54x = 678.36 × 281.72
  4. Step 4: Simplify right side
    491.54x = 191,107.58
  5. Step 5: Solve for x
    x = 191,107.58/491.54
  6. Step 6: Final answer
    x = 388.79

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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.