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Finding the Fourth Proportional to 660.40, 911.46 and 380.68

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Solution

The fourth proportional to 660.40, 911.46 and 380.68 is: 525.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.40 : 911.46 = 380.68 : x
  2. Step 2: Convert to fraction form
    660.40/911.46 = 380.68/x
  3. Step 3: Cross multiply
    660.40x = 911.46 × 380.68
  4. Step 4: Simplify right side
    660.40x = 346,974.59
  5. Step 5: Solve for x
    x = 346,974.59/660.40
  6. Step 6: Final answer
    x = 525.40

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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.