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Finding the Fourth Proportional to 871.38, 1,301.40 and 780.66

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Solution

The fourth proportional to 871.38, 1,301.40 and 780.66 is: 1,165.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.38 : 1,301.40 = 780.66 : x
  2. Step 2: Convert to fraction form
    871.38/1,301.40 = 780.66/x
  3. Step 3: Cross multiply
    871.38x = 1,301.40 × 780.66
  4. Step 4: Simplify right side
    871.38x = 1,015,950.92
  5. Step 5: Solve for x
    x = 1,015,950.92/871.38
  6. Step 6: Final answer
    x = 1,165.91

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.