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Finding the Fourth Proportional to 255.39, 383.08 and 72.78

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Solution

The fourth proportional to 255.39, 383.08 and 72.78 is: 109.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    255.39 : 383.08 = 72.78 : x
  2. Step 2: Convert to fraction form
    255.39/383.08 = 72.78/x
  3. Step 3: Cross multiply
    255.39x = 383.08 × 72.78
  4. Step 4: Simplify right side
    255.39x = 27,880.56
  5. Step 5: Solve for x
    x = 27,880.56/255.39
  6. Step 6: Final answer
    x = 109.17

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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.