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Finding the Fourth Proportional to 678.83, 1,018.63 and 419.47

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Solution

The fourth proportional to 678.83, 1,018.63 and 419.47 is: 629.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.83 : 1,018.63 = 419.47 : x
  2. Step 2: Convert to fraction form
    678.83/1,018.63 = 419.47/x
  3. Step 3: Cross multiply
    678.83x = 1,018.63 × 419.47
  4. Step 4: Simplify right side
    678.83x = 427,277.54
  5. Step 5: Solve for x
    x = 427,277.54/678.83
  6. Step 6: Final answer
    x = 629.43

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.