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Finding the Fourth Proportional to 811.52, 1,120 and 742.40

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Solution

The fourth proportional to 811.52, 1,120 and 742.40 is: 1,024.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.52 : 1,120 = 742.40 : x
  2. Step 2: Convert to fraction form
    811.52/1,120 = 742.40/x
  3. Step 3: Cross multiply
    811.52x = 1,120 × 742.40
  4. Step 4: Simplify right side
    811.52x = 831,488
  5. Step 5: Solve for x
    x = 831,488/811.52
  6. Step 6: Final answer
    x = 1,024.61

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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.