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Finding the Fourth Proportional to 320.50, 480.75 and 89.40

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Solution

The fourth proportional to 320.50, 480.75 and 89.40 is: 134.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.50 : 480.75 = 89.40 : x
  2. Step 2: Convert to fraction form
    320.50/480.75 = 89.40/x
  3. Step 3: Cross multiply
    320.50x = 480.75 × 89.40
  4. Step 4: Simplify right side
    320.50x = 42,980.85
  5. Step 5: Solve for x
    x = 42,980.85/320.50
  6. Step 6: Final answer
    x = 134.11

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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.