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Finding the Fourth Proportional to 716.79, 988.22 and 643.89

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Solution

The fourth proportional to 716.79, 988.22 and 643.89 is: 887.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    716.79 : 988.22 = 643.89 : x
  2. Step 2: Convert to fraction form
    716.79/988.22 = 643.89/x
  3. Step 3: Cross multiply
    716.79x = 988.22 × 643.89
  4. Step 4: Simplify right side
    716.79x = 636,304.98
  5. Step 5: Solve for x
    x = 636,304.98/716.79
  6. Step 6: Final answer
    x = 887.71

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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.