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Finding the Fourth Proportional to 780.85, 1,171.26 and 318.52

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Solution

The fourth proportional to 780.85, 1,171.26 and 318.52 is: 477.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.85 : 1,171.26 = 318.52 : x
  2. Step 2: Convert to fraction form
    780.85/1,171.26 = 318.52/x
  3. Step 3: Cross multiply
    780.85x = 1,171.26 × 318.52
  4. Step 4: Simplify right side
    780.85x = 373,063.88
  5. Step 5: Solve for x
    x = 373,063.88/780.85
  6. Step 6: Final answer
    x = 477.77

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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.