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Finding the Fourth Proportional to 421.81, 632.72 and 205.45

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Solution

The fourth proportional to 421.81, 632.72 and 205.45 is: 308.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.81 : 632.72 = 205.45 : x
  2. Step 2: Convert to fraction form
    421.81/632.72 = 205.45/x
  3. Step 3: Cross multiply
    421.81x = 632.72 × 205.45
  4. Step 4: Simplify right side
    421.81x = 129,991.30
  5. Step 5: Solve for x
    x = 129,991.30/421.81
  6. Step 6: Final answer
    x = 308.18

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.