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Finding the Fourth Proportional to 660.69, 911.86 and 395.15

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Solution

The fourth proportional to 660.69, 911.86 and 395.15 is: 545.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.69 : 911.86 = 395.15 : x
  2. Step 2: Convert to fraction form
    660.69/911.86 = 395.15/x
  3. Step 3: Cross multiply
    660.69x = 911.86 × 395.15
  4. Step 4: Simplify right side
    660.69x = 360,315.93
  5. Step 5: Solve for x
    x = 360,315.93/660.69
  6. Step 6: Final answer
    x = 545.36

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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.