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Finding the Fourth Proportional to 491.52, 678.20 and 281.70

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Solution

The fourth proportional to 491.52, 678.20 and 281.70 is: 388.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.52 : 678.20 = 281.70 : x
  2. Step 2: Convert to fraction form
    491.52/678.20 = 281.70/x
  3. Step 3: Cross multiply
    491.52x = 678.20 × 281.70
  4. Step 4: Simplify right side
    491.52x = 191,048.94
  5. Step 5: Solve for x
    x = 191,048.94/491.52
  6. Step 6: Final answer
    x = 388.69

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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.