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Finding the Fourth Proportional to 259.59, 387.12 and 221.31

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Solution

The fourth proportional to 259.59, 387.12 and 221.31 is: 330.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    259.59 : 387.12 = 221.31 : x
  2. Step 2: Convert to fraction form
    259.59/387.12 = 221.31/x
  3. Step 3: Cross multiply
    259.59x = 387.12 × 221.31
  4. Step 4: Simplify right side
    259.59x = 85,673.53
  5. Step 5: Solve for x
    x = 85,673.53/259.59
  6. Step 6: Final answer
    x = 330.03

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.