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Finding the Fourth Proportional to 660.61, 911.57 and 395

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Solution

The fourth proportional to 660.61, 911.57 and 395 is: 545.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.61 : 911.57 = 395 : x
  2. Step 2: Convert to fraction form
    660.61/911.57 = 395/x
  3. Step 3: Cross multiply
    660.61x = 911.57 × 395
  4. Step 4: Simplify right side
    660.61x = 360,070.15
  5. Step 5: Solve for x
    x = 360,070.15/660.61
  6. Step 6: Final answer
    x = 545.06

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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.