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Finding the Fourth Proportional to 780.68, 1,168.14 and 685.64

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Solution

The fourth proportional to 780.68, 1,168.14 and 685.64 is: 1,025.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.68 : 1,168.14 = 685.64 : x
  2. Step 2: Convert to fraction form
    780.68/1,168.14 = 685.64/x
  3. Step 3: Cross multiply
    780.68x = 1,168.14 × 685.64
  4. Step 4: Simplify right side
    780.68x = 800,923.51
  5. Step 5: Solve for x
    x = 800,923.51/780.68
  6. Step 6: Final answer
    x = 1,025.93

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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.