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Finding the Fourth Proportional to 661.12, 989.80 and 335.80

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Solution

The fourth proportional to 661.12, 989.80 and 335.80 is: 502.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.12 : 989.80 = 335.80 : x
  2. Step 2: Convert to fraction form
    661.12/989.80 = 335.80/x
  3. Step 3: Cross multiply
    661.12x = 989.80 × 335.80
  4. Step 4: Simplify right side
    661.12x = 332,374.84
  5. Step 5: Solve for x
    x = 332,374.84/661.12
  6. Step 6: Final answer
    x = 502.75

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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.