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Finding the Fourth Proportional to 305.44, 420.78 and 256.60

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Solution

The fourth proportional to 305.44, 420.78 and 256.60 is: 353.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.44 : 420.78 = 256.60 : x
  2. Step 2: Convert to fraction form
    305.44/420.78 = 256.60/x
  3. Step 3: Cross multiply
    305.44x = 420.78 × 256.60
  4. Step 4: Simplify right side
    305.44x = 107,972.15
  5. Step 5: Solve for x
    x = 107,972.15/305.44
  6. Step 6: Final answer
    x = 353.50

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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.