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Finding the Fourth Proportional to 646.20, 969.30 and 399.60

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Solution

The fourth proportional to 646.20, 969.30 and 399.60 is: 599.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.20 : 969.30 = 399.60 : x
  2. Step 2: Convert to fraction form
    646.20/969.30 = 399.60/x
  3. Step 3: Cross multiply
    646.20x = 969.30 × 399.60
  4. Step 4: Simplify right side
    646.20x = 387,332.28
  5. Step 5: Solve for x
    x = 387,332.28/646.20
  6. Step 6: Final answer
    x = 599.40

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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.