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Finding the Fourth Proportional to 145.58, 216.90 and 138.70

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Solution

The fourth proportional to 145.58, 216.90 and 138.70 is: 206.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.58 : 216.90 = 138.70 : x
  2. Step 2: Convert to fraction form
    145.58/216.90 = 138.70/x
  3. Step 3: Cross multiply
    145.58x = 216.90 × 138.70
  4. Step 4: Simplify right side
    145.58x = 30,084.03
  5. Step 5: Solve for x
    x = 30,084.03/145.58
  6. Step 6: Final answer
    x = 206.65

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.