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Finding the Fourth Proportional to 808.98, 1,118.64 and 642.90

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Solution

The fourth proportional to 808.98, 1,118.64 and 642.90 is: 888.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.98 : 1,118.64 = 642.90 : x
  2. Step 2: Convert to fraction form
    808.98/1,118.64 = 642.90/x
  3. Step 3: Cross multiply
    808.98x = 1,118.64 × 642.90
  4. Step 4: Simplify right side
    808.98x = 719,173.66
  5. Step 5: Solve for x
    x = 719,173.66/808.98
  6. Step 6: Final answer
    x = 888.99

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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.