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Finding the Fourth Proportional to 143.45, 214.95 and 139.65

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Solution

The fourth proportional to 143.45, 214.95 and 139.65 is: 209.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.45 : 214.95 = 139.65 : x
  2. Step 2: Convert to fraction form
    143.45/214.95 = 139.65/x
  3. Step 3: Cross multiply
    143.45x = 214.95 × 139.65
  4. Step 4: Simplify right side
    143.45x = 30,017.61
  5. Step 5: Solve for x
    x = 30,017.61/143.45
  6. Step 6: Final answer
    x = 209.25

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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.