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Finding the Fourth Proportional to 145.81, 218.90 and 115.40

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Solution

The fourth proportional to 145.81, 218.90 and 115.40 is: 173.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.81 : 218.90 = 115.40 : x
  2. Step 2: Convert to fraction form
    145.81/218.90 = 115.40/x
  3. Step 3: Cross multiply
    145.81x = 218.90 × 115.40
  4. Step 4: Simplify right side
    145.81x = 25,261.06
  5. Step 5: Solve for x
    x = 25,261.06/145.81
  6. Step 6: Final answer
    x = 173.25

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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.