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Finding the Fourth Proportional to 807.51, 1,209.75 and 721.71

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Solution

The fourth proportional to 807.51, 1,209.75 and 721.71 is: 1,081.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.51 : 1,209.75 = 721.71 : x
  2. Step 2: Convert to fraction form
    807.51/1,209.75 = 721.71/x
  3. Step 3: Cross multiply
    807.51x = 1,209.75 × 721.71
  4. Step 4: Simplify right side
    807.51x = 873,088.67
  5. Step 5: Solve for x
    x = 873,088.67/807.51
  6. Step 6: Final answer
    x = 1,081.21

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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.