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Finding the Fourth Proportional to 657.78, 908.37 and 621.42

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Solution

The fourth proportional to 657.78, 908.37 and 621.42 is: 858.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    657.78 : 908.37 = 621.42 : x
  2. Step 2: Convert to fraction form
    657.78/908.37 = 621.42/x
  3. Step 3: Cross multiply
    657.78x = 908.37 × 621.42
  4. Step 4: Simplify right side
    657.78x = 564,479.29
  5. Step 5: Solve for x
    x = 564,479.29/657.78
  6. Step 6: Final answer
    x = 858.16

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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.