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Finding the Fourth Proportional to 40.08, 55.28 and 30.40

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Solution

The fourth proportional to 40.08, 55.28 and 30.40 is: 41.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    40.08 : 55.28 = 30.40 : x
  2. Step 2: Convert to fraction form
    40.08/55.28 = 30.40/x
  3. Step 3: Cross multiply
    40.08x = 55.28 × 30.40
  4. Step 4: Simplify right side
    40.08x = 1,680.51
  5. Step 5: Solve for x
    x = 1,680.51/40.08
  6. Step 6: Final answer
    x = 41.93

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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.