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Finding the Fourth Proportional to 785.04, 1,081.20 and 644.71

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Solution

The fourth proportional to 785.04, 1,081.20 and 644.71 is: 887.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.04 : 1,081.20 = 644.71 : x
  2. Step 2: Convert to fraction form
    785.04/1,081.20 = 644.71/x
  3. Step 3: Cross multiply
    785.04x = 1,081.20 × 644.71
  4. Step 4: Simplify right side
    785.04x = 697,058.57
  5. Step 5: Solve for x
    x = 697,058.57/785.04
  6. Step 6: Final answer
    x = 887.93

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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.