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Finding the Fourth Proportional to 780.36, 1,171.07 and 415.41

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Solution

The fourth proportional to 780.36, 1,171.07 and 415.41 is: 623.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.36 : 1,171.07 = 415.41 : x
  2. Step 2: Convert to fraction form
    780.36/1,171.07 = 415.41/x
  3. Step 3: Cross multiply
    780.36x = 1,171.07 × 415.41
  4. Step 4: Simplify right side
    780.36x = 486,472.11
  5. Step 5: Solve for x
    x = 486,472.11/780.36
  6. Step 6: Final answer
    x = 623.39

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.