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Finding the Fourth Proportional to 699.90, 965.78 and 420.06

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Solution

The fourth proportional to 699.90, 965.78 and 420.06 is: 579.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    699.90 : 965.78 = 420.06 : x
  2. Step 2: Convert to fraction form
    699.90/965.78 = 420.06/x
  3. Step 3: Cross multiply
    699.90x = 965.78 × 420.06
  4. Step 4: Simplify right side
    699.90x = 405,685.55
  5. Step 5: Solve for x
    x = 405,685.55/699.90
  6. Step 6: Final answer
    x = 579.63

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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.