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Finding the Fourth Proportional to 661.22, 989.80 and 557.81

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Solution

The fourth proportional to 661.22, 989.80 and 557.81 is: 835.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.22 : 989.80 = 557.81 : x
  2. Step 2: Convert to fraction form
    661.22/989.80 = 557.81/x
  3. Step 3: Cross multiply
    661.22x = 989.80 × 557.81
  4. Step 4: Simplify right side
    661.22x = 552,120.34
  5. Step 5: Solve for x
    x = 552,120.34/661.22
  6. Step 6: Final answer
    x = 835.00

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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.