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Finding the Fourth Proportional to 145.15, 199.86 and 128.55

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Solution

The fourth proportional to 145.15, 199.86 and 128.55 is: 177.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.15 : 199.86 = 128.55 : x
  2. Step 2: Convert to fraction form
    145.15/199.86 = 128.55/x
  3. Step 3: Cross multiply
    145.15x = 199.86 × 128.55
  4. Step 4: Simplify right side
    145.15x = 25,692.00
  5. Step 5: Solve for x
    x = 25,692.00/145.15
  6. Step 6: Final answer
    x = 177.00

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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.