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Finding the Fourth Proportional to 72.79, 100.45 and 40.04

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Solution

The fourth proportional to 72.79, 100.45 and 40.04 is: 55.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.79 : 100.45 = 40.04 : x
  2. Step 2: Convert to fraction form
    72.79/100.45 = 40.04/x
  3. Step 3: Cross multiply
    72.79x = 100.45 × 40.04
  4. Step 4: Simplify right side
    72.79x = 4,021.42
  5. Step 5: Solve for x
    x = 4,021.42/72.79
  6. Step 6: Final answer
    x = 55.25

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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.