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Finding the Fourth Proportional to 777.81, 1,073.80 and 638.29

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Solution

The fourth proportional to 777.81, 1,073.80 and 638.29 is: 881.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    777.81 : 1,073.80 = 638.29 : x
  2. Step 2: Convert to fraction form
    777.81/1,073.80 = 638.29/x
  3. Step 3: Cross multiply
    777.81x = 1,073.80 × 638.29
  4. Step 4: Simplify right side
    777.81x = 685,395.80
  5. Step 5: Solve for x
    x = 685,395.80/777.81
  6. Step 6: Final answer
    x = 881.19

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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.