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Finding the Fourth Proportional to 665.21, 916.41 and 636.05

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Solution

The fourth proportional to 665.21, 916.41 and 636.05 is: 876.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.21 : 916.41 = 636.05 : x
  2. Step 2: Convert to fraction form
    665.21/916.41 = 636.05/x
  3. Step 3: Cross multiply
    665.21x = 916.41 × 636.05
  4. Step 4: Simplify right side
    665.21x = 582,887.26
  5. Step 5: Solve for x
    x = 582,887.26/665.21
  6. Step 6: Final answer
    x = 876.24

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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.