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Finding the Fourth Proportional to 395.40, 545.40 and 255.42

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Solution

The fourth proportional to 395.40, 545.40 and 255.42 is: 352.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    395.40 : 545.40 = 255.42 : x
  2. Step 2: Convert to fraction form
    395.40/545.40 = 255.42/x
  3. Step 3: Cross multiply
    395.40x = 545.40 × 255.42
  4. Step 4: Simplify right side
    395.40x = 139,306.07
  5. Step 5: Solve for x
    x = 139,306.07/395.40
  6. Step 6: Final answer
    x = 352.32

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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.