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Finding the Fourth Proportional to 286.94, 429.60 and 257.78

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Solution

The fourth proportional to 286.94, 429.60 and 257.78 is: 385.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.94 : 429.60 = 257.78 : x
  2. Step 2: Convert to fraction form
    286.94/429.60 = 257.78/x
  3. Step 3: Cross multiply
    286.94x = 429.60 × 257.78
  4. Step 4: Simplify right side
    286.94x = 110,742.29
  5. Step 5: Solve for x
    x = 110,742.29/286.94
  6. Step 6: Final answer
    x = 385.94

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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.