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Finding the Fourth Proportional to 309.74, 427.08 and 257.35

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Solution

The fourth proportional to 309.74, 427.08 and 257.35 is: 354.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.74 : 427.08 = 257.35 : x
  2. Step 2: Convert to fraction form
    309.74/427.08 = 257.35/x
  3. Step 3: Cross multiply
    309.74x = 427.08 × 257.35
  4. Step 4: Simplify right side
    309.74x = 109,906.90
  5. Step 5: Solve for x
    x = 109,906.90/309.74
  6. Step 6: Final answer
    x = 354.84

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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.