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Finding the Fourth Proportional to 853.40, 1,279.94 and 511

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Solution

The fourth proportional to 853.40, 1,279.94 and 511 is: 766.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.40 : 1,279.94 = 511 : x
  2. Step 2: Convert to fraction form
    853.40/1,279.94 = 511/x
  3. Step 3: Cross multiply
    853.40x = 1,279.94 × 511
  4. Step 4: Simplify right side
    853.40x = 654,049.34
  5. Step 5: Solve for x
    x = 654,049.34/853.40
  6. Step 6: Final answer
    x = 766.40

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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.