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Finding the Fourth Proportional to 660.91, 912.09 and 395.40

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Solution

The fourth proportional to 660.91, 912.09 and 395.40 is: 545.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.91 : 912.09 = 395.40 : x
  2. Step 2: Convert to fraction form
    660.91/912.09 = 395.40/x
  3. Step 3: Cross multiply
    660.91x = 912.09 × 395.40
  4. Step 4: Simplify right side
    660.91x = 360,639.61
  5. Step 5: Solve for x
    x = 360,639.61/660.91
  6. Step 6: Final answer
    x = 545.67

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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.