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Finding the Fourth Proportional to 398.04, 545.66 and 391.66

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Solution

The fourth proportional to 398.04, 545.66 and 391.66 is: 536.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.04 : 545.66 = 391.66 : x
  2. Step 2: Convert to fraction form
    398.04/545.66 = 391.66/x
  3. Step 3: Cross multiply
    398.04x = 545.66 × 391.66
  4. Step 4: Simplify right side
    398.04x = 213,711.34
  5. Step 5: Solve for x
    x = 213,711.34/398.04
  6. Step 6: Final answer
    x = 536.91

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.