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Finding the Fourth Proportional to 660.49, 911.30 and 380.80

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Solution

The fourth proportional to 660.49, 911.30 and 380.80 is: 525.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.49 : 911.30 = 380.80 : x
  2. Step 2: Convert to fraction form
    660.49/911.30 = 380.80/x
  3. Step 3: Cross multiply
    660.49x = 911.30 × 380.80
  4. Step 4: Simplify right side
    660.49x = 347,023.04
  5. Step 5: Solve for x
    x = 347,023.04/660.49
  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.