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Finding the Fourth Proportional to 643.58, 965.64 and 278.64

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Solution

The fourth proportional to 643.58, 965.64 and 278.64 is: 418.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.58 : 965.64 = 278.64 : x
  2. Step 2: Convert to fraction form
    643.58/965.64 = 278.64/x
  3. Step 3: Cross multiply
    643.58x = 965.64 × 278.64
  4. Step 4: Simplify right side
    643.58x = 269,065.93
  5. Step 5: Solve for x
    x = 269,065.93/643.58
  6. Step 6: Final answer
    x = 418.08

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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.