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Finding the Fourth Proportional to 811.20, 1,120.32 and 578.88

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Solution

The fourth proportional to 811.20, 1,120.32 and 578.88 is: 799.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.20 : 1,120.32 = 578.88 : x
  2. Step 2: Convert to fraction form
    811.20/1,120.32 = 578.88/x
  3. Step 3: Cross multiply
    811.20x = 1,120.32 × 578.88
  4. Step 4: Simplify right side
    811.20x = 648,530.84
  5. Step 5: Solve for x
    x = 648,530.84/811.20
  6. Step 6: Final answer
    x = 799.47

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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.