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Finding the Fourth Proportional to 752.80, 1,039.20 and 487.36

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Solution

The fourth proportional to 752.80, 1,039.20 and 487.36 is: 672.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    752.80 : 1,039.20 = 487.36 : x
  2. Step 2: Convert to fraction form
    752.80/1,039.20 = 487.36/x
  3. Step 3: Cross multiply
    752.80x = 1,039.20 × 487.36
  4. Step 4: Simplify right side
    752.80x = 506,464.51
  5. Step 5: Solve for x
    x = 506,464.51/752.80
  6. Step 6: Final answer
    x = 672.77

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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.