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Finding the Fourth Proportional to 31.79, 47.65 and 19.75

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Solution

The fourth proportional to 31.79, 47.65 and 19.75 is: 29.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.79 : 47.65 = 19.75 : x
  2. Step 2: Convert to fraction form
    31.79/47.65 = 19.75/x
  3. Step 3: Cross multiply
    31.79x = 47.65 × 19.75
  4. Step 4: Simplify right side
    31.79x = 941.09
  5. Step 5: Solve for x
    x = 941.09/31.79
  6. Step 6: Final answer
    x = 29.60

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.