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Finding the Fourth Proportional to 660.76, 911.70 and 398.77

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Solution

The fourth proportional to 660.76, 911.70 and 398.77 is: 550.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.76 : 911.70 = 398.77 : x
  2. Step 2: Convert to fraction form
    660.76/911.70 = 398.77/x
  3. Step 3: Cross multiply
    660.76x = 911.70 × 398.77
  4. Step 4: Simplify right side
    660.76x = 363,554.05
  5. Step 5: Solve for x
    x = 363,554.05/660.76
  6. Step 6: Final answer
    x = 550.21

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1.5x scale

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.