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Finding the Fourth Proportional to 780.49, 1,171.26 and 415.53

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Solution

The fourth proportional to 780.49, 1,171.26 and 415.53 is: 623.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.49 : 1,171.26 = 415.53 : x
  2. Step 2: Convert to fraction form
    780.49/1,171.26 = 415.53/x
  3. Step 3: Cross multiply
    780.49x = 1,171.26 × 415.53
  4. Step 4: Simplify right side
    780.49x = 486,693.67
  5. Step 5: Solve for x
    x = 486,693.67/780.49
  6. Step 6: Final answer
    x = 623.58

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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.