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Finding the Fourth Proportional to 1,206.38, 1,808.69 and 815.40

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Solution

The fourth proportional to 1,206.38, 1,808.69 and 815.40 is: 1,222.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,206.38 : 1,808.69 = 815.40 : x
  2. Step 2: Convert to fraction form
    1,206.38/1,808.69 = 815.40/x
  3. Step 3: Cross multiply
    1,206.38x = 1,808.69 × 815.40
  4. Step 4: Simplify right side
    1,206.38x = 1,474,801.75
  5. Step 5: Solve for x
    x = 1,474,801.75/1,206.38
  6. Step 6: Final answer
    x = 1,222.51

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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.