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Finding the Fourth Proportional to 395.79, 545.82 and 312.75

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Solution

The fourth proportional to 395.79, 545.82 and 312.75 is: 431.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    395.79 : 545.82 = 312.75 : x
  2. Step 2: Convert to fraction form
    395.79/545.82 = 312.75/x
  3. Step 3: Cross multiply
    395.79x = 545.82 × 312.75
  4. Step 4: Simplify right side
    395.79x = 170,705.21
  5. Step 5: Solve for x
    x = 170,705.21/395.79
  6. Step 6: Final answer
    x = 431.30

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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.