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Finding the Fourth Proportional to 780.80, 1,171.98 and 561.68

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Solution

The fourth proportional to 780.80, 1,171.98 and 561.68 is: 843.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.80 : 1,171.98 = 561.68 : x
  2. Step 2: Convert to fraction form
    780.80/1,171.98 = 561.68/x
  3. Step 3: Cross multiply
    780.80x = 1,171.98 × 561.68
  4. Step 4: Simplify right side
    780.80x = 658,276.26
  5. Step 5: Solve for x
    x = 658,276.26/780.80
  6. Step 6: Final answer
    x = 843.08

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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.