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Finding the Fourth Proportional to 1,311.86, 1,810.26 and 787.79

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Solution

The fourth proportional to 1,311.86, 1,810.26 and 787.79 is: 1,087.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,311.86 : 1,810.26 = 787.79 : x
  2. Step 2: Convert to fraction form
    1,311.86/1,810.26 = 787.79/x
  3. Step 3: Cross multiply
    1,311.86x = 1,810.26 × 787.79
  4. Step 4: Simplify right side
    1,311.86x = 1,426,095.67
  5. Step 5: Solve for x
    x = 1,426,095.67/1,311.86
  6. Step 6: Final answer
    x = 1,087.08

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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.