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Finding the Fourth Proportional to 643.93, 965.71 and 319.21

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Solution

The fourth proportional to 643.93, 965.71 and 319.21 is: 478.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.93 : 965.71 = 319.21 : x
  2. Step 2: Convert to fraction form
    643.93/965.71 = 319.21/x
  3. Step 3: Cross multiply
    643.93x = 965.71 × 319.21
  4. Step 4: Simplify right side
    643.93x = 308,264.29
  5. Step 5: Solve for x
    x = 308,264.29/643.93
  6. Step 6: Final answer
    x = 478.72

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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.