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Finding the Fourth Proportional to 310.84, 427.65 and 257.78

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Solution

The fourth proportional to 310.84, 427.65 and 257.78 is: 354.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.84 : 427.65 = 257.78 : x
  2. Step 2: Convert to fraction form
    310.84/427.65 = 257.78/x
  3. Step 3: Cross multiply
    310.84x = 427.65 × 257.78
  4. Step 4: Simplify right side
    310.84x = 110,239.62
  5. Step 5: Solve for x
    x = 110,239.62/310.84
  6. Step 6: Final answer
    x = 354.65

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.