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Finding the Fourth Proportional to 909.66, 1,255.29 and 643.83

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Solution

The fourth proportional to 909.66, 1,255.29 and 643.83 is: 888.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    909.66 : 1,255.29 = 643.83 : x
  2. Step 2: Convert to fraction form
    909.66/1,255.29 = 643.83/x
  3. Step 3: Cross multiply
    909.66x = 1,255.29 × 643.83
  4. Step 4: Simplify right side
    909.66x = 808,193.36
  5. Step 5: Solve for x
    x = 808,193.36/909.66
  6. Step 6: Final answer
    x = 888.46

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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.