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Finding the Fourth Proportional to 258.59, 385.59 and 255.40

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Solution

The fourth proportional to 258.59, 385.59 and 255.40 is: 380.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.59 : 385.59 = 255.40 : x
  2. Step 2: Convert to fraction form
    258.59/385.59 = 255.40/x
  3. Step 3: Cross multiply
    258.59x = 385.59 × 255.40
  4. Step 4: Simplify right side
    258.59x = 98,479.69
  5. Step 5: Solve for x
    x = 98,479.69/258.59
  6. Step 6: Final answer
    x = 380.83

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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.