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Finding the Fourth Proportional to 781.84, 1,071.20 and 771.58

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Solution

The fourth proportional to 781.84, 1,071.20 and 771.58 is: 1,057.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.84 : 1,071.20 = 771.58 : x
  2. Step 2: Convert to fraction form
    781.84/1,071.20 = 771.58/x
  3. Step 3: Cross multiply
    781.84x = 1,071.20 × 771.58
  4. Step 4: Simplify right side
    781.84x = 826,516.50
  5. Step 5: Solve for x
    x = 826,516.50/781.84
  6. Step 6: Final answer
    x = 1,057.14

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.