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Finding the Fourth Proportional to 813.75, 1,122.52 and 720.51

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Solution

The fourth proportional to 813.75, 1,122.52 and 720.51 is: 993.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.75 : 1,122.52 = 720.51 : x
  2. Step 2: Convert to fraction form
    813.75/1,122.52 = 720.51/x
  3. Step 3: Cross multiply
    813.75x = 1,122.52 × 720.51
  4. Step 4: Simplify right side
    813.75x = 808,786.89
  5. Step 5: Solve for x
    x = 808,786.89/813.75
  6. Step 6: Final answer
    x = 993.90

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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.