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Finding the Fourth Proportional to 1,310.76, 1,808.81 and 721.30

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Solution

The fourth proportional to 1,310.76, 1,808.81 and 721.30 is: 995.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,310.76 : 1,808.81 = 721.30 : x
  2. Step 2: Convert to fraction form
    1,310.76/1,808.81 = 721.30/x
  3. Step 3: Cross multiply
    1,310.76x = 1,808.81 × 721.30
  4. Step 4: Simplify right side
    1,310.76x = 1,304,691.93
  5. Step 5: Solve for x
    x = 1,304,691.93/1,310.76
  6. Step 6: Final answer
    x = 995.37

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1.5x scale

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.