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Finding the Fourth Proportional to 1,287.72, 1,932.84 and 917.93

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Solution

The fourth proportional to 1,287.72, 1,932.84 and 917.93 is: 1,377.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.72 : 1,932.84 = 917.93 : x
  2. Step 2: Convert to fraction form
    1,287.72/1,932.84 = 917.93/x
  3. Step 3: Cross multiply
    1,287.72x = 1,932.84 × 917.93
  4. Step 4: Simplify right side
    1,287.72x = 1,774,202.16
  5. Step 5: Solve for x
    x = 1,774,202.16/1,287.72
  6. Step 6: Final answer
    x = 1,377.79

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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.