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Finding the Fourth Proportional to 679.50, 1,013.07 and 638.19

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Solution

The fourth proportional to 679.50, 1,013.07 and 638.19 is: 951.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.50 : 1,013.07 = 638.19 : x
  2. Step 2: Convert to fraction form
    679.50/1,013.07 = 638.19/x
  3. Step 3: Cross multiply
    679.50x = 1,013.07 × 638.19
  4. Step 4: Simplify right side
    679.50x = 646,531.14
  5. Step 5: Solve for x
    x = 646,531.14/679.50
  6. Step 6: Final answer
    x = 951.48

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.