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Finding the Fourth Proportional to 518.64, 777.94 and 128.64

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Solution

The fourth proportional to 518.64, 777.94 and 128.64 is: 192.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.64 : 777.94 = 128.64 : x
  2. Step 2: Convert to fraction form
    518.64/777.94 = 128.64/x
  3. Step 3: Cross multiply
    518.64x = 777.94 × 128.64
  4. Step 4: Simplify right side
    518.64x = 100,074.61
  5. Step 5: Solve for x
    x = 100,074.61/518.64
  6. Step 6: Final answer
    x = 192.96

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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.