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Finding the Fourth Proportional to 320, 480 and 206.40

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Solution

The fourth proportional to 320, 480 and 206.40 is: 309.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    320 : 480 = 206.40 : x
  2. Step 2: Convert to fraction form
    320/480 = 206.40/x
  3. Step 3: Cross multiply
    320x = 480 × 206.40
  4. Step 4: Simplify right side
    320x = 99,072
  5. Step 5: Solve for x
    x = 99,072/320
  6. Step 6: Final answer
    x = 309.60

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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.