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Finding the Fourth Proportional to 780.81, 1,079.88 and 697.77

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Solution

The fourth proportional to 780.81, 1,079.88 and 697.77 is: 965.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.81 : 1,079.88 = 697.77 : x
  2. Step 2: Convert to fraction form
    780.81/1,079.88 = 697.77/x
  3. Step 3: Cross multiply
    780.81x = 1,079.88 × 697.77
  4. Step 4: Simplify right side
    780.81x = 753,507.87
  5. Step 5: Solve for x
    x = 753,507.87/780.81
  6. Step 6: Final answer
    x = 965.03

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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.