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Finding the Fourth Proportional to 281.05, 387.78 and 211.34

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Solution

The fourth proportional to 281.05, 387.78 and 211.34 is: 291.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    281.05 : 387.78 = 211.34 : x
  2. Step 2: Convert to fraction form
    281.05/387.78 = 211.34/x
  3. Step 3: Cross multiply
    281.05x = 387.78 × 211.34
  4. Step 4: Simplify right side
    281.05x = 81,953.43
  5. Step 5: Solve for x
    x = 81,953.43/281.05
  6. Step 6: Final answer
    x = 291.60

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.