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Finding the Fourth Proportional to 1,209.78, 1,815.23 and 661.14

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Solution

The fourth proportional to 1,209.78, 1,815.23 and 661.14 is: 992.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,209.78 : 1,815.23 = 661.14 : x
  2. Step 2: Convert to fraction form
    1,209.78/1,815.23 = 661.14/x
  3. Step 3: Cross multiply
    1,209.78x = 1,815.23 × 661.14
  4. Step 4: Simplify right side
    1,209.78x = 1,200,121.16
  5. Step 5: Solve for x
    x = 1,200,121.16/1,209.78
  6. Step 6: Final answer
    x = 992.02

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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.