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Finding the Fourth Proportional to 780.42, 1,169.12 and 725.60

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Solution

The fourth proportional to 780.42, 1,169.12 and 725.60 is: 1,087.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.42 : 1,169.12 = 725.60 : x
  2. Step 2: Convert to fraction form
    780.42/1,169.12 = 725.60/x
  3. Step 3: Cross multiply
    780.42x = 1,169.12 × 725.60
  4. Step 4: Simplify right side
    780.42x = 848,313.47
  5. Step 5: Solve for x
    x = 848,313.47/780.42
  6. Step 6: Final answer
    x = 1,087.00

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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.