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Finding the Fourth Proportional to 281.09, 421.70 and 118.78

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Solution

The fourth proportional to 281.09, 421.70 and 118.78 is: 178.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    281.09 : 421.70 = 118.78 : x
  2. Step 2: Convert to fraction form
    281.09/421.70 = 118.78/x
  3. Step 3: Cross multiply
    281.09x = 421.70 × 118.78
  4. Step 4: Simplify right side
    281.09x = 50,089.53
  5. Step 5: Solve for x
    x = 50,089.53/281.09
  6. Step 6: Final answer
    x = 178.20

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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.