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Finding the Fourth Proportional to 145.30, 216.78 and 129.90

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Solution

The fourth proportional to 145.30, 216.78 and 129.90 is: 193.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.30 : 216.78 = 129.90 : x
  2. Step 2: Convert to fraction form
    145.30/216.78 = 129.90/x
  3. Step 3: Cross multiply
    145.30x = 216.78 × 129.90
  4. Step 4: Simplify right side
    145.30x = 28,159.72
  5. Step 5: Solve for x
    x = 28,159.72/145.30
  6. Step 6: Final answer
    x = 193.80

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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.