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Finding the Fourth Proportional to 305.28, 421.74 and 258.57

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Solution

The fourth proportional to 305.28, 421.74 and 258.57 is: 357.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.28 : 421.74 = 258.57 : x
  2. Step 2: Convert to fraction form
    305.28/421.74 = 258.57/x
  3. Step 3: Cross multiply
    305.28x = 421.74 × 258.57
  4. Step 4: Simplify right side
    305.28x = 109,049.31
  5. Step 5: Solve for x
    x = 109,049.31/305.28
  6. Step 6: Final answer
    x = 357.21

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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.