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Finding the Fourth Proportional to 620.02, 855.30 and 387.28

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Solution

The fourth proportional to 620.02, 855.30 and 387.28 is: 534.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.02 : 855.30 = 387.28 : x
  2. Step 2: Convert to fraction form
    620.02/855.30 = 387.28/x
  3. Step 3: Cross multiply
    620.02x = 855.30 × 387.28
  4. Step 4: Simplify right side
    620.02x = 331,240.58
  5. Step 5: Solve for x
    x = 331,240.58/620.02
  6. Step 6: Final answer
    x = 534.24

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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.