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Finding the Fourth Proportional to 258.71, 387.21 and 141.40

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Solution

The fourth proportional to 258.71, 387.21 and 141.40 is: 211.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.71 : 387.21 = 141.40 : x
  2. Step 2: Convert to fraction form
    258.71/387.21 = 141.40/x
  3. Step 3: Cross multiply
    258.71x = 387.21 × 141.40
  4. Step 4: Simplify right side
    258.71x = 54,751.49
  5. Step 5: Solve for x
    x = 54,751.49/258.71
  6. Step 6: Final answer
    x = 211.63

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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.