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Finding the Fourth Proportional to 678.98, 1,018.37 and 313.74

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Solution

The fourth proportional to 678.98, 1,018.37 and 313.74 is: 470.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.98 : 1,018.37 = 313.74 : x
  2. Step 2: Convert to fraction form
    678.98/1,018.37 = 313.74/x
  3. Step 3: Cross multiply
    678.98x = 1,018.37 × 313.74
  4. Step 4: Simplify right side
    678.98x = 319,504.19
  5. Step 5: Solve for x
    x = 319,504.19/678.98
  6. Step 6: Final answer
    x = 470.56

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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.