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Finding the Fourth Proportional to 491.30, 678.04 and 281.55

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Solution

The fourth proportional to 491.30, 678.04 and 281.55 is: 388.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.30 : 678.04 = 281.55 : x
  2. Step 2: Convert to fraction form
    491.30/678.04 = 281.55/x
  3. Step 3: Cross multiply
    491.30x = 678.04 × 281.55
  4. Step 4: Simplify right side
    491.30x = 190,898.92
  5. Step 5: Solve for x
    x = 190,898.92/491.30
  6. Step 6: Final answer
    x = 388.56

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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.