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Finding the Fourth Proportional to 853.76, 1,177.68 and 643.84

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Solution

The fourth proportional to 853.76, 1,177.68 and 643.84 is: 888.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.76 : 1,177.68 = 643.84 : x
  2. Step 2: Convert to fraction form
    853.76/1,177.68 = 643.84/x
  3. Step 3: Cross multiply
    853.76x = 1,177.68 × 643.84
  4. Step 4: Simplify right side
    853.76x = 758,237.49
  5. Step 5: Solve for x
    x = 758,237.49/853.76
  6. Step 6: Final answer
    x = 888.12

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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.