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Finding the Fourth Proportional to 395.28, 545.20 and 307.76

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Solution

The fourth proportional to 395.28, 545.20 and 307.76 is: 424.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    395.28 : 545.20 = 307.76 : x
  2. Step 2: Convert to fraction form
    395.28/545.20 = 307.76/x
  3. Step 3: Cross multiply
    395.28x = 545.20 × 307.76
  4. Step 4: Simplify right side
    395.28x = 167,790.75
  5. Step 5: Solve for x
    x = 167,790.75/395.28
  6. Step 6: Final answer
    x = 424.49

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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.