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Finding the Fourth Proportional to 1,379.84, 1,903.92 and 856

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Solution

The fourth proportional to 1,379.84, 1,903.92 and 856 is: 1,181.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,379.84 : 1,903.92 = 856 : x
  2. Step 2: Convert to fraction form
    1,379.84/1,903.92 = 856/x
  3. Step 3: Cross multiply
    1,379.84x = 1,903.92 × 856
  4. Step 4: Simplify right side
    1,379.84x = 1,629,755.52
  5. Step 5: Solve for x
    x = 1,629,755.52/1,379.84
  6. Step 6: Final answer
    x = 1,181.12

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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.