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Finding the Fourth Proportional to 421.95, 632.80 and 129.43

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Solution

The fourth proportional to 421.95, 632.80 and 129.43 is: 194.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.95 : 632.80 = 129.43 : x
  2. Step 2: Convert to fraction form
    421.95/632.80 = 129.43/x
  3. Step 3: Cross multiply
    421.95x = 632.80 × 129.43
  4. Step 4: Simplify right side
    421.95x = 81,903.30
  5. Step 5: Solve for x
    x = 81,903.30/421.95
  6. Step 6: Final answer
    x = 194.11

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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.