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Finding the Fourth Proportional to 388.47, 536.55 and 288.72

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Solution

The fourth proportional to 388.47, 536.55 and 288.72 is: 398.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.47 : 536.55 = 288.72 : x
  2. Step 2: Convert to fraction form
    388.47/536.55 = 288.72/x
  3. Step 3: Cross multiply
    388.47x = 536.55 × 288.72
  4. Step 4: Simplify right side
    388.47x = 154,912.72
  5. Step 5: Solve for x
    x = 154,912.72/388.47
  6. Step 6: Final answer
    x = 398.78

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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.