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Finding the Fourth Proportional to 780.10, 1,076.16 and 500.11

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Solution

The fourth proportional to 780.10, 1,076.16 and 500.11 is: 689.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.10 : 1,076.16 = 500.11 : x
  2. Step 2: Convert to fraction form
    780.10/1,076.16 = 500.11/x
  3. Step 3: Cross multiply
    780.10x = 1,076.16 × 500.11
  4. Step 4: Simplify right side
    780.10x = 538,198.38
  5. Step 5: Solve for x
    x = 538,198.38/780.10
  6. Step 6: Final answer
    x = 689.91

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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.