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Finding the Fourth Proportional to 780.69, 1,077.74 and 486.05

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Solution

The fourth proportional to 780.69, 1,077.74 and 486.05 is: 670.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.69 : 1,077.74 = 486.05 : x
  2. Step 2: Convert to fraction form
    780.69/1,077.74 = 486.05/x
  3. Step 3: Cross multiply
    780.69x = 1,077.74 × 486.05
  4. Step 4: Simplify right side
    780.69x = 523,835.53
  5. Step 5: Solve for x
    x = 523,835.53/780.69
  6. Step 6: Final answer
    x = 670.99

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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.