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Finding the Fourth Proportional to 699.78, 965.40 and 420.02

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Solution

The fourth proportional to 699.78, 965.40 and 420.02 is: 579.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    699.78 : 965.40 = 420.02 : x
  2. Step 2: Convert to fraction form
    699.78/965.40 = 420.02/x
  3. Step 3: Cross multiply
    699.78x = 965.40 × 420.02
  4. Step 4: Simplify right side
    699.78x = 405,482.48
  5. Step 5: Solve for x
    x = 405,482.48/699.78
  6. Step 6: Final answer
    x = 579.44

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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.