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Finding the Fourth Proportional to 813.29, 1,220.64 and 720.95

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Solution

The fourth proportional to 813.29, 1,220.64 and 720.95 is: 1,082.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.29 : 1,220.64 = 720.95 : x
  2. Step 2: Convert to fraction form
    813.29/1,220.64 = 720.95/x
  3. Step 3: Cross multiply
    813.29x = 1,220.64 × 720.95
  4. Step 4: Simplify right side
    813.29x = 880,010.70
  5. Step 5: Solve for x
    x = 880,010.70/813.29
  6. Step 6: Final answer
    x = 1,082.04

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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.