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Finding the Fourth Proportional to 780.82, 1,077.25 and 501.20

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Solution

The fourth proportional to 780.82, 1,077.25 and 501.20 is: 691.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.82 : 1,077.25 = 501.20 : x
  2. Step 2: Convert to fraction form
    780.82/1,077.25 = 501.20/x
  3. Step 3: Cross multiply
    780.82x = 1,077.25 × 501.20
  4. Step 4: Simplify right side
    780.82x = 539,917.70
  5. Step 5: Solve for x
    x = 539,917.70/780.82
  6. Step 6: Final answer
    x = 691.48

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.