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Finding the Fourth Proportional to 660.16, 990.60 and 399.52

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Solution

The fourth proportional to 660.16, 990.60 and 399.52 is: 599.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.16 : 990.60 = 399.52 : x
  2. Step 2: Convert to fraction form
    660.16/990.60 = 399.52/x
  3. Step 3: Cross multiply
    660.16x = 990.60 × 399.52
  4. Step 4: Simplify right side
    660.16x = 395,764.51
  5. Step 5: Solve for x
    x = 395,764.51/660.16
  6. Step 6: Final answer
    x = 599.50

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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.