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Finding the Fourth Proportional to 679.20, 1,018.80 and 216.98

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Solution

The fourth proportional to 679.20, 1,018.80 and 216.98 is: 325.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.20 : 1,018.80 = 216.98 : x
  2. Step 2: Convert to fraction form
    679.20/1,018.80 = 216.98/x
  3. Step 3: Cross multiply
    679.20x = 1,018.80 × 216.98
  4. Step 4: Simplify right side
    679.20x = 221,061.77
  5. Step 5: Solve for x
    x = 221,061.77/679.20
  6. Step 6: Final answer
    x = 325.47

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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.