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Finding the Fourth Proportional to 421.72, 632.82 and 389.08

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Solution

The fourth proportional to 421.72, 632.82 and 389.08 is: 583.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.72 : 632.82 = 389.08 : x
  2. Step 2: Convert to fraction form
    421.72/632.82 = 389.08/x
  3. Step 3: Cross multiply
    421.72x = 632.82 × 389.08
  4. Step 4: Simplify right side
    421.72x = 246,217.61
  5. Step 5: Solve for x
    x = 246,217.61/421.72
  6. Step 6: Final answer
    x = 583.84

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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.