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Finding the Fourth Proportional to 421.79, 632.84 and 285.39

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Solution

The fourth proportional to 421.79, 632.84 and 285.39 is: 428.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.79 : 632.84 = 285.39 : x
  2. Step 2: Convert to fraction form
    421.79/632.84 = 285.39/x
  3. Step 3: Cross multiply
    421.79x = 632.84 × 285.39
  4. Step 4: Simplify right side
    421.79x = 180,604.78
  5. Step 5: Solve for x
    x = 180,604.78/421.79
  6. Step 6: Final answer
    x = 428.19

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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.