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Finding the Fourth Proportional to 618.72, 854.30 and 397.80

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Solution

The fourth proportional to 618.72, 854.30 and 397.80 is: 549.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.72 : 854.30 = 397.80 : x
  2. Step 2: Convert to fraction form
    618.72/854.30 = 397.80/x
  3. Step 3: Cross multiply
    618.72x = 854.30 × 397.80
  4. Step 4: Simplify right side
    618.72x = 339,838.55
  5. Step 5: Solve for x
    x = 339,838.55/618.72
  6. Step 6: Final answer
    x = 549.26

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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.