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Finding the Fourth Proportional to 305.80, 421.86 and 189.34

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Solution

The fourth proportional to 305.80, 421.86 and 189.34 is: 261.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.80 : 421.86 = 189.34 : x
  2. Step 2: Convert to fraction form
    305.80/421.86 = 189.34/x
  3. Step 3: Cross multiply
    305.80x = 421.86 × 189.34
  4. Step 4: Simplify right side
    305.80x = 79,874.97
  5. Step 5: Solve for x
    x = 79,874.97/305.80
  6. Step 6: Final answer
    x = 261.20

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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.