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Finding the Fourth Proportional to 660.79, 911.79 and 395.15

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Solution

The fourth proportional to 660.79, 911.79 and 395.15 is: 545.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.79 : 911.79 = 395.15 : x
  2. Step 2: Convert to fraction form
    660.79/911.79 = 395.15/x
  3. Step 3: Cross multiply
    660.79x = 911.79 × 395.15
  4. Step 4: Simplify right side
    660.79x = 360,293.82
  5. Step 5: Solve for x
    x = 360,293.82/660.79
  6. Step 6: Final answer
    x = 545.25

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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.