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Finding the Fourth Proportional to 638.78, 955.94 and 553.13

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Solution

The fourth proportional to 638.78, 955.94 and 553.13 is: 827.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.78 : 955.94 = 553.13 : x
  2. Step 2: Convert to fraction form
    638.78/955.94 = 553.13/x
  3. Step 3: Cross multiply
    638.78x = 955.94 × 553.13
  4. Step 4: Simplify right side
    638.78x = 528,751.55
  5. Step 5: Solve for x
    x = 528,751.55/638.78
  6. Step 6: Final answer
    x = 827.76

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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.