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Finding the Fourth Proportional to 305.70, 421.91 and 207.42

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Solution

The fourth proportional to 305.70, 421.91 and 207.42 is: 286.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.70 : 421.91 = 207.42 : x
  2. Step 2: Convert to fraction form
    305.70/421.91 = 207.42/x
  3. Step 3: Cross multiply
    305.70x = 421.91 × 207.42
  4. Step 4: Simplify right side
    305.70x = 87,512.57
  5. Step 5: Solve for x
    x = 87,512.57/305.70
  6. Step 6: Final answer
    x = 286.27

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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.