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Finding the Fourth Proportional to 643.88, 964.77 and 619.91

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Solution

The fourth proportional to 643.88, 964.77 and 619.91 is: 928.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.88 : 964.77 = 619.91 : x
  2. Step 2: Convert to fraction form
    643.88/964.77 = 619.91/x
  3. Step 3: Cross multiply
    643.88x = 964.77 × 619.91
  4. Step 4: Simplify right side
    643.88x = 598,070.57
  5. Step 5: Solve for x
    x = 598,070.57/643.88
  6. Step 6: Final answer
    x = 928.85

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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.