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Finding the Fourth Proportional to 1,105, 1,658.31 and 721.06

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Solution

The fourth proportional to 1,105, 1,658.31 and 721.06 is: 1,082.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,105 : 1,658.31 = 721.06 : x
  2. Step 2: Convert to fraction form
    1,105/1,658.31 = 721.06/x
  3. Step 3: Cross multiply
    1,105x = 1,658.31 × 721.06
  4. Step 4: Simplify right side
    1,105x = 1,195,741.01
  5. Step 5: Solve for x
    x = 1,195,741.01/1,105
  6. Step 6: Final answer
    x = 1,082.12

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Double scale
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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.