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Finding the Fourth Proportional to 628.12, 867 and 395.40

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Solution

The fourth proportional to 628.12, 867 and 395.40 is: 545.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.12 : 867 = 395.40 : x
  2. Step 2: Convert to fraction form
    628.12/867 = 395.40/x
  3. Step 3: Cross multiply
    628.12x = 867 × 395.40
  4. Step 4: Simplify right side
    628.12x = 342,811.80
  5. Step 5: Solve for x
    x = 342,811.80/628.12
  6. Step 6: Final answer
    x = 545.77

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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.