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Finding the Fourth Proportional to 421.86, 632.84 and 257.61

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Solution

The fourth proportional to 421.86, 632.84 and 257.61 is: 386.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.86 : 632.84 = 257.61 : x
  2. Step 2: Convert to fraction form
    421.86/632.84 = 257.61/x
  3. Step 3: Cross multiply
    421.86x = 632.84 × 257.61
  4. Step 4: Simplify right side
    421.86x = 163,024.62
  5. Step 5: Solve for x
    x = 163,024.62/421.86
  6. Step 6: Final answer
    x = 386.44

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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.