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Finding the Fourth Proportional to 486.39, 728.31 and 388.44

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Solution

The fourth proportional to 486.39, 728.31 and 388.44 is: 581.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.39 : 728.31 = 388.44 : x
  2. Step 2: Convert to fraction form
    486.39/728.31 = 388.44/x
  3. Step 3: Cross multiply
    486.39x = 728.31 × 388.44
  4. Step 4: Simplify right side
    486.39x = 282,904.74
  5. Step 5: Solve for x
    x = 282,904.74/486.39
  6. Step 6: Final answer
    x = 581.64

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.