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Finding the Fourth Proportional to 306.24, 421.44 and 257.76

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Solution

The fourth proportional to 306.24, 421.44 and 257.76 is: 354.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    306.24 : 421.44 = 257.76 : x
  2. Step 2: Convert to fraction form
    306.24/421.44 = 257.76/x
  3. Step 3: Cross multiply
    306.24x = 421.44 × 257.76
  4. Step 4: Simplify right side
    306.24x = 108,630.37
  5. Step 5: Solve for x
    x = 108,630.37/306.24
  6. Step 6: Final answer
    x = 354.72

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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.