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Finding the Fourth Proportional to 668.72, 922.59 and 388.91

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Solution

The fourth proportional to 668.72, 922.59 and 388.91 is: 536.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.72 : 922.59 = 388.91 : x
  2. Step 2: Convert to fraction form
    668.72/922.59 = 388.91/x
  3. Step 3: Cross multiply
    668.72x = 922.59 × 388.91
  4. Step 4: Simplify right side
    668.72x = 358,806.78
  5. Step 5: Solve for x
    x = 358,806.78/668.72
  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.