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Finding the Fourth Proportional to 807.20, 1,112.80 and 670.40

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Solution

The fourth proportional to 807.20, 1,112.80 and 670.40 is: 924.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.20 : 1,112.80 = 670.40 : x
  2. Step 2: Convert to fraction form
    807.20/1,112.80 = 670.40/x
  3. Step 3: Cross multiply
    807.20x = 1,112.80 × 670.40
  4. Step 4: Simplify right side
    807.20x = 746,021.12
  5. Step 5: Solve for x
    x = 746,021.12/807.20
  6. Step 6: Final answer
    x = 924.21

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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.