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Finding the Fourth Proportional to 28.47, 39.25 and 21.19

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Solution

The fourth proportional to 28.47, 39.25 and 21.19 is: 29.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.47 : 39.25 = 21.19 : x
  2. Step 2: Convert to fraction form
    28.47/39.25 = 21.19/x
  3. Step 3: Cross multiply
    28.47x = 39.25 × 21.19
  4. Step 4: Simplify right side
    28.47x = 831.71
  5. Step 5: Solve for x
    x = 831.71/28.47
  6. Step 6: Final answer
    x = 29.21

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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.