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Finding the Fourth Proportional to 30.38, 45.57 and 21.40

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Solution

The fourth proportional to 30.38, 45.57 and 21.40 is: 32.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.38 : 45.57 = 21.40 : x
  2. Step 2: Convert to fraction form
    30.38/45.57 = 21.40/x
  3. Step 3: Cross multiply
    30.38x = 45.57 × 21.40
  4. Step 4: Simplify right side
    30.38x = 975.20
  5. Step 5: Solve for x
    x = 975.20/30.38
  6. Step 6: Final answer
    x = 32.10

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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.