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Finding the Fourth Proportional to 780.89, 1,171.80 and 521.10

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Solution

The fourth proportional to 780.89, 1,171.80 and 521.10 is: 781.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.89 : 1,171.80 = 521.10 : x
  2. Step 2: Convert to fraction form
    780.89/1,171.80 = 521.10/x
  3. Step 3: Cross multiply
    780.89x = 1,171.80 × 521.10
  4. Step 4: Simplify right side
    780.89x = 610,624.98
  5. Step 5: Solve for x
    x = 610,624.98/780.89
  6. Step 6: Final answer
    x = 781.97

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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.