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Finding the Fourth Proportional to 778.98, 1,071.31 and 619.74

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Solution

The fourth proportional to 778.98, 1,071.31 and 619.74 is: 852.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.98 : 1,071.31 = 619.74 : x
  2. Step 2: Convert to fraction form
    778.98/1,071.31 = 619.74/x
  3. Step 3: Cross multiply
    778.98x = 1,071.31 × 619.74
  4. Step 4: Simplify right side
    778.98x = 663,933.66
  5. Step 5: Solve for x
    x = 663,933.66/778.98
  6. Step 6: Final answer
    x = 852.31

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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.