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Finding the Fourth Proportional to 780.10, 1,076.12 and 465.21

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Solution

The fourth proportional to 780.10, 1,076.12 and 465.21 is: 641.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.10 : 1,076.12 = 465.21 : x
  2. Step 2: Convert to fraction form
    780.10/1,076.12 = 465.21/x
  3. Step 3: Cross multiply
    780.10x = 1,076.12 × 465.21
  4. Step 4: Simplify right side
    780.10x = 500,621.20
  5. Step 5: Solve for x
    x = 500,621.20/780.10
  6. Step 6: Final answer
    x = 641.74

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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.