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Finding the Fourth Proportional to 491.91, 678.94 and 282.12

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Solution

The fourth proportional to 491.91, 678.94 and 282.12 is: 389.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.91 : 678.94 = 282.12 : x
  2. Step 2: Convert to fraction form
    491.91/678.94 = 282.12/x
  3. Step 3: Cross multiply
    491.91x = 678.94 × 282.12
  4. Step 4: Simplify right side
    491.91x = 191,542.55
  5. Step 5: Solve for x
    x = 191,542.55/491.91
  6. Step 6: Final answer
    x = 389.39

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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.