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Finding the Fourth Proportional to 506.78, 699.18 and 388.64

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Solution

The fourth proportional to 506.78, 699.18 and 388.64 is: 536.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    506.78 : 699.18 = 388.64 : x
  2. Step 2: Convert to fraction form
    506.78/699.18 = 388.64/x
  3. Step 3: Cross multiply
    506.78x = 699.18 × 388.64
  4. Step 4: Simplify right side
    506.78x = 271,729.32
  5. Step 5: Solve for x
    x = 271,729.32/506.78
  6. Step 6: Final answer
    x = 536.19

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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.