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Finding the Fourth Proportional to 699.77, 965.85 and 405.21

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Solution

The fourth proportional to 699.77, 965.85 and 405.21 is: 559.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    699.77 : 965.85 = 405.21 : x
  2. Step 2: Convert to fraction form
    699.77/965.85 = 405.21/x
  3. Step 3: Cross multiply
    699.77x = 965.85 × 405.21
  4. Step 4: Simplify right side
    699.77x = 391,367.25
  5. Step 5: Solve for x
    x = 391,367.25/699.77
  6. Step 6: Final answer
    x = 559.28

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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.