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Finding the Fourth Proportional to 31.07, 42.95 and 28.19

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Solution

The fourth proportional to 31.07, 42.95 and 28.19 is: 38.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.07 : 42.95 = 28.19 : x
  2. Step 2: Convert to fraction form
    31.07/42.95 = 28.19/x
  3. Step 3: Cross multiply
    31.07x = 42.95 × 28.19
  4. Step 4: Simplify right side
    31.07x = 1,210.62
  5. Step 5: Solve for x
    x = 1,210.62/31.07
  6. Step 6: Final answer
    x = 38.96

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1.5x scale

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.