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Finding the Fourth Proportional to 880.80, 1,321.80 and 515.20

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Solution

The fourth proportional to 880.80, 1,321.80 and 515.20 is: 773.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    880.80 : 1,321.80 = 515.20 : x
  2. Step 2: Convert to fraction form
    880.80/1,321.80 = 515.20/x
  3. Step 3: Cross multiply
    880.80x = 1,321.80 × 515.20
  4. Step 4: Simplify right side
    880.80x = 680,991.36
  5. Step 5: Solve for x
    x = 680,991.36/880.80
  6. Step 6: Final answer
    x = 773.15

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.