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Finding the Fourth Proportional to 677.16, 1,015.54 and 639.90

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Solution

The fourth proportional to 677.16, 1,015.54 and 639.90 is: 959.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    677.16 : 1,015.54 = 639.90 : x
  2. Step 2: Convert to fraction form
    677.16/1,015.54 = 639.90/x
  3. Step 3: Cross multiply
    677.16x = 1,015.54 × 639.90
  4. Step 4: Simplify right side
    677.16x = 649,842.45
  5. Step 5: Solve for x
    x = 649,842.45/677.16
  6. Step 6: Final answer
    x = 959.66

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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.