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Finding the Fourth Proportional to 145.55, 200.80 and 90.31

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Solution

The fourth proportional to 145.55, 200.80 and 90.31 is: 124.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.55 : 200.80 = 90.31 : x
  2. Step 2: Convert to fraction form
    145.55/200.80 = 90.31/x
  3. Step 3: Cross multiply
    145.55x = 200.80 × 90.31
  4. Step 4: Simplify right side
    145.55x = 18,134.25
  5. Step 5: Solve for x
    x = 18,134.25/145.55
  6. Step 6: Final answer
    x = 124.59

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.