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Finding the Fourth Proportional to 310.25, 427.64 and 257.70

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Solution

The fourth proportional to 310.25, 427.64 and 257.70 is: 355.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.25 : 427.64 = 257.70 : x
  2. Step 2: Convert to fraction form
    310.25/427.64 = 257.70/x
  3. Step 3: Cross multiply
    310.25x = 427.64 × 257.70
  4. Step 4: Simplify right side
    310.25x = 110,202.83
  5. Step 5: Solve for x
    x = 110,202.83/310.25
  6. Step 6: Final answer
    x = 355.21

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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.