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Finding the Fourth Proportional to 668.78, 922.68 and 388.91

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Solution

The fourth proportional to 668.78, 922.68 and 388.91 is: 536.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.78 : 922.68 = 388.91 : x
  2. Step 2: Convert to fraction form
    668.78/922.68 = 388.91/x
  3. Step 3: Cross multiply
    668.78x = 922.68 × 388.91
  4. Step 4: Simplify right side
    668.78x = 358,842.54
  5. Step 5: Solve for x
    x = 358,842.54/668.78
  6. Step 6: Final answer
    x = 536.56

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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.