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Finding the Fourth Proportional to 679.49, 1,018.95 and 217.15

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Solution

The fourth proportional to 679.49, 1,018.95 and 217.15 is: 325.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.49 : 1,018.95 = 217.15 : x
  2. Step 2: Convert to fraction form
    679.49/1,018.95 = 217.15/x
  3. Step 3: Cross multiply
    679.49x = 1,018.95 × 217.15
  4. Step 4: Simplify right side
    679.49x = 221,264.99
  5. Step 5: Solve for x
    x = 221,264.99/679.49
  6. Step 6: Final answer
    x = 325.63

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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.