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Finding the Fourth Proportional to 30.95, 42.73 and 21.75

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Solution

The fourth proportional to 30.95, 42.73 and 21.75 is: 30.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.95 : 42.73 = 21.75 : x
  2. Step 2: Convert to fraction form
    30.95/42.73 = 21.75/x
  3. Step 3: Cross multiply
    30.95x = 42.73 × 21.75
  4. Step 4: Simplify right side
    30.95x = 929.38
  5. Step 5: Solve for x
    x = 929.38/30.95
  6. Step 6: Final answer
    x = 30.03

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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.