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Finding the Fourth Proportional to 853.76, 1,281.28 and 636.80

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Solution

The fourth proportional to 853.76, 1,281.28 and 636.80 is: 955.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.76 : 1,281.28 = 636.80 : x
  2. Step 2: Convert to fraction form
    853.76/1,281.28 = 636.80/x
  3. Step 3: Cross multiply
    853.76x = 1,281.28 × 636.80
  4. Step 4: Simplify right side
    853.76x = 815,919.10
  5. Step 5: Solve for x
    x = 815,919.10/853.76
  6. Step 6: Final answer
    x = 955.68

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.