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Finding the Fourth Proportional to 518.38, 777.56 and 128.38

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Solution

The fourth proportional to 518.38, 777.56 and 128.38 is: 192.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.38 : 777.56 = 128.38 : x
  2. Step 2: Convert to fraction form
    518.38/777.56 = 128.38/x
  3. Step 3: Cross multiply
    518.38x = 777.56 × 128.38
  4. Step 4: Simplify right side
    518.38x = 99,823.15
  5. Step 5: Solve for x
    x = 99,823.15/518.38
  6. Step 6: Final answer
    x = 192.57

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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.