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Finding the Fourth Proportional to 388.71, 536.56 and 257.76

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Solution

The fourth proportional to 388.71, 536.56 and 257.76 is: 355.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.71 : 536.56 = 257.76 : x
  2. Step 2: Convert to fraction form
    388.71/536.56 = 257.76/x
  3. Step 3: Cross multiply
    388.71x = 536.56 × 257.76
  4. Step 4: Simplify right side
    388.71x = 138,303.06
  5. Step 5: Solve for x
    x = 138,303.06/388.71
  6. Step 6: Final answer
    x = 355.80

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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.