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Finding the Fourth Proportional to 421.98, 632.80 and 205.39

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Solution

The fourth proportional to 421.98, 632.80 and 205.39 is: 308.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.98 : 632.80 = 205.39 : x
  2. Step 2: Convert to fraction form
    421.98/632.80 = 205.39/x
  3. Step 3: Cross multiply
    421.98x = 632.80 × 205.39
  4. Step 4: Simplify right side
    421.98x = 129,970.79
  5. Step 5: Solve for x
    x = 129,970.79/421.98
  6. Step 6: Final answer
    x = 308.00

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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.