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Finding the Fourth Proportional to 846.78, 1,169.40 and 644.55

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Solution

The fourth proportional to 846.78, 1,169.40 and 644.55 is: 890.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    846.78 : 1,169.40 = 644.55 : x
  2. Step 2: Convert to fraction form
    846.78/1,169.40 = 644.55/x
  3. Step 3: Cross multiply
    846.78x = 1,169.40 × 644.55
  4. Step 4: Simplify right side
    846.78x = 753,736.77
  5. Step 5: Solve for x
    x = 753,736.77/846.78
  6. Step 6: Final answer
    x = 890.12

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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.