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Finding the Fourth Proportional to 652, 978 and 408.40

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Solution

The fourth proportional to 652, 978 and 408.40 is: 612.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    652 : 978 = 408.40 : x
  2. Step 2: Convert to fraction form
    652/978 = 408.40/x
  3. Step 3: Cross multiply
    652x = 978 × 408.40
  4. Step 4: Simplify right side
    652x = 399,415.20
  5. Step 5: Solve for x
    x = 399,415.20/652
  6. Step 6: Final answer
    x = 612.60

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These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.