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Finding the Fourth Proportional to 780.57, 1,169.86 and 317.81

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Solution

The fourth proportional to 780.57, 1,169.86 and 317.81 is: 476.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.57 : 1,169.86 = 317.81 : x
  2. Step 2: Convert to fraction form
    780.57/1,169.86 = 317.81/x
  3. Step 3: Cross multiply
    780.57x = 1,169.86 × 317.81
  4. Step 4: Simplify right side
    780.57x = 371,789.35
  5. Step 5: Solve for x
    x = 371,789.35/780.57
  6. Step 6: Final answer
    x = 476.30

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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.