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Finding the Fourth Proportional to 305.88, 421.38 and 256.74

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Solution

The fourth proportional to 305.88, 421.38 and 256.74 is: 353.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.88 : 421.38 = 256.74 : x
  2. Step 2: Convert to fraction form
    305.88/421.38 = 256.74/x
  3. Step 3: Cross multiply
    305.88x = 421.38 × 256.74
  4. Step 4: Simplify right side
    305.88x = 108,185.10
  5. Step 5: Solve for x
    x = 108,185.10/305.88
  6. Step 6: Final answer
    x = 353.68

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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.