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Finding the Fourth Proportional to 258.47, 386.43 and 220.40

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Solution

The fourth proportional to 258.47, 386.43 and 220.40 is: 329.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.47 : 386.43 = 220.40 : x
  2. Step 2: Convert to fraction form
    258.47/386.43 = 220.40/x
  3. Step 3: Cross multiply
    258.47x = 386.43 × 220.40
  4. Step 4: Simplify right side
    258.47x = 85,167.24
  5. Step 5: Solve for x
    x = 85,167.24/258.47
  6. Step 6: Final answer
    x = 329.51

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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.