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Finding the Fourth Proportional to 388.71, 536.57 and 257.90

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Solution

The fourth proportional to 388.71, 536.57 and 257.90 is: 355.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.71 : 536.57 = 257.90 : x
  2. Step 2: Convert to fraction form
    388.71/536.57 = 257.90/x
  3. Step 3: Cross multiply
    388.71x = 536.57 × 257.90
  4. Step 4: Simplify right side
    388.71x = 138,377.43
  5. Step 5: Solve for x
    x = 138,377.43/388.71
  6. Step 6: Final answer
    x = 355.99

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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.