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Finding the Fourth Proportional to 421.82, 632.80 and 257.41

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Solution

The fourth proportional to 421.82, 632.80 and 257.41 is: 386.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.82 : 632.80 = 257.41 : x
  2. Step 2: Convert to fraction form
    421.82/632.80 = 257.41/x
  3. Step 3: Cross multiply
    421.82x = 632.80 × 257.41
  4. Step 4: Simplify right side
    421.82x = 162,889.05
  5. Step 5: Solve for x
    x = 162,889.05/421.82
  6. Step 6: Final answer
    x = 386.16

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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.