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Finding the Fourth Proportional to 258.30, 387.45 and 256.41

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Solution

The fourth proportional to 258.30, 387.45 and 256.41 is: 384.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.30 : 387.45 = 256.41 : x
  2. Step 2: Convert to fraction form
    258.30/387.45 = 256.41/x
  3. Step 3: Cross multiply
    258.30x = 387.45 × 256.41
  4. Step 4: Simplify right side
    258.30x = 99,346.05
  5. Step 5: Solve for x
    x = 99,346.05/258.30
  6. Step 6: Final answer
    x = 384.62

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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.