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Finding the Fourth Proportional to 313.20, 432.72 and 287.28

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Solution

The fourth proportional to 313.20, 432.72 and 287.28 is: 396.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    313.20 : 432.72 = 287.28 : x
  2. Step 2: Convert to fraction form
    313.20/432.72 = 287.28/x
  3. Step 3: Cross multiply
    313.20x = 432.72 × 287.28
  4. Step 4: Simplify right side
    313.20x = 124,311.80
  5. Step 5: Solve for x
    x = 124,311.80/313.20
  6. Step 6: Final answer
    x = 396.91

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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.