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Finding the Fourth Proportional to 718.40, 992.24 and 644.80

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Solution

The fourth proportional to 718.40, 992.24 and 644.80 is: 890.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.40 : 992.24 = 644.80 : x
  2. Step 2: Convert to fraction form
    718.40/992.24 = 644.80/x
  3. Step 3: Cross multiply
    718.40x = 992.24 × 644.80
  4. Step 4: Simplify right side
    718.40x = 639,796.35
  5. Step 5: Solve for x
    x = 639,796.35/718.40
  6. Step 6: Final answer
    x = 890.59

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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.