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Finding the Fourth Proportional to 660.44, 989.55 and 399.65

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Solution

The fourth proportional to 660.44, 989.55 and 399.65 is: 598.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.44 : 989.55 = 399.65 : x
  2. Step 2: Convert to fraction form
    660.44/989.55 = 399.65/x
  3. Step 3: Cross multiply
    660.44x = 989.55 × 399.65
  4. Step 4: Simplify right side
    660.44x = 395,476.45
  5. Step 5: Solve for x
    x = 395,476.45/660.44
  6. Step 6: Final answer
    x = 598.81

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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.