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Finding the Fourth Proportional to 330.72, 455.28 and 287.52

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Solution

The fourth proportional to 330.72, 455.28 and 287.52 is: 395.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    330.72 : 455.28 = 287.52 : x
  2. Step 2: Convert to fraction form
    330.72/455.28 = 287.52/x
  3. Step 3: Cross multiply
    330.72x = 455.28 × 287.52
  4. Step 4: Simplify right side
    330.72x = 130,902.11
  5. Step 5: Solve for x
    x = 130,902.11/330.72
  6. Step 6: Final answer
    x = 395.81

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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.