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Finding the Fourth Proportional to 678.22, 1,015.03 and 418.39

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Solution

The fourth proportional to 678.22, 1,015.03 and 418.39 is: 626.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.22 : 1,015.03 = 418.39 : x
  2. Step 2: Convert to fraction form
    678.22/1,015.03 = 418.39/x
  3. Step 3: Cross multiply
    678.22x = 1,015.03 × 418.39
  4. Step 4: Simplify right side
    678.22x = 424,679.24
  5. Step 5: Solve for x
    x = 424,679.24/678.22
  6. Step 6: Final answer
    x = 626.16

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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.