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Finding the Fourth Proportional to 781.71, 1,173.05 and 319.49

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Solution

The fourth proportional to 781.71, 1,173.05 and 319.49 is: 479.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.71 : 1,173.05 = 319.49 : x
  2. Step 2: Convert to fraction form
    781.71/1,173.05 = 319.49/x
  3. Step 3: Cross multiply
    781.71x = 1,173.05 × 319.49
  4. Step 4: Simplify right side
    781.71x = 374,775.88
  5. Step 5: Solve for x
    x = 374,775.88/781.71
  6. Step 6: Final answer
    x = 479.43

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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.