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Finding the Fourth Proportional to 643.95, 966.08 and 279.15

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Solution

The fourth proportional to 643.95, 966.08 and 279.15 is: 418.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.95 : 966.08 = 279.15 : x
  2. Step 2: Convert to fraction form
    643.95/966.08 = 279.15/x
  3. Step 3: Cross multiply
    643.95x = 966.08 × 279.15
  4. Step 4: Simplify right side
    643.95x = 269,681.23
  5. Step 5: Solve for x
    x = 269,681.23/643.95
  6. Step 6: Final answer
    x = 418.79

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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.