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Finding the Fourth Proportional to 30.79, 42.67 and 27.75

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Solution

The fourth proportional to 30.79, 42.67 and 27.75 is: 38.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.79 : 42.67 = 27.75 : x
  2. Step 2: Convert to fraction form
    30.79/42.67 = 27.75/x
  3. Step 3: Cross multiply
    30.79x = 42.67 × 27.75
  4. Step 4: Simplify right side
    30.79x = 1,184.02
  5. Step 5: Solve for x
    x = 1,184.02/30.79
  6. Step 6: Final answer
    x = 38.46

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Find fourth proportional to 15.39, 21.33 and 13.88
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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.