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Finding the Fourth Proportional to 780.46, 1,170.86 and 415.19

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Solution

The fourth proportional to 780.46, 1,170.86 and 415.19 is: 622.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.46 : 1,170.86 = 415.19 : x
  2. Step 2: Convert to fraction form
    780.46/1,170.86 = 415.19/x
  3. Step 3: Cross multiply
    780.46x = 1,170.86 × 415.19
  4. Step 4: Simplify right side
    780.46x = 486,130.21
  5. Step 5: Solve for x
    x = 486,130.21/780.46
  6. Step 6: Final answer
    x = 622.88

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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.