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Finding the Fourth Proportional to 679.12, 1,018.20 and 313.36

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Solution

The fourth proportional to 679.12, 1,018.20 and 313.36 is: 469.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.12 : 1,018.20 = 313.36 : x
  2. Step 2: Convert to fraction form
    679.12/1,018.20 = 313.36/x
  3. Step 3: Cross multiply
    679.12x = 1,018.20 × 313.36
  4. Step 4: Simplify right side
    679.12x = 319,063.15
  5. Step 5: Solve for x
    x = 319,063.15/679.12
  6. Step 6: Final answer
    x = 469.82

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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.