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Finding the Fourth Proportional to 782.05, 1,173.21 and 319.81

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Solution

The fourth proportional to 782.05, 1,173.21 and 319.81 is: 479.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.05 : 1,173.21 = 319.81 : x
  2. Step 2: Convert to fraction form
    782.05/1,173.21 = 319.81/x
  3. Step 3: Cross multiply
    782.05x = 1,173.21 × 319.81
  4. Step 4: Simplify right side
    782.05x = 375,204.29
  5. Step 5: Solve for x
    x = 375,204.29/782.05
  6. Step 6: Final answer
    x = 479.77

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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.