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Finding the Fourth Proportional to 781.30, 1,077.42 and 501.49

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Solution

The fourth proportional to 781.30, 1,077.42 and 501.49 is: 691.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.30 : 1,077.42 = 501.49 : x
  2. Step 2: Convert to fraction form
    781.30/1,077.42 = 501.49/x
  3. Step 3: Cross multiply
    781.30x = 1,077.42 × 501.49
  4. Step 4: Simplify right side
    781.30x = 540,315.36
  5. Step 5: Solve for x
    x = 540,315.36/781.30
  6. Step 6: Final answer
    x = 691.56

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.