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Finding the Fourth Proportional to 780.77, 1,171.37 and 342

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Solution

The fourth proportional to 780.77, 1,171.37 and 342 is: 513.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.77 : 1,171.37 = 342 : x
  2. Step 2: Convert to fraction form
    780.77/1,171.37 = 342/x
  3. Step 3: Cross multiply
    780.77x = 1,171.37 × 342
  4. Step 4: Simplify right side
    780.77x = 400,609.40
  5. Step 5: Solve for x
    x = 400,609.40/780.77
  6. Step 6: Final answer
    x = 513.09

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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.