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Finding the Fourth Proportional to 420.19, 630.15 and 146.20

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Solution

The fourth proportional to 420.19, 630.15 and 146.20 is: 219.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.19 : 630.15 = 146.20 : x
  2. Step 2: Convert to fraction form
    420.19/630.15 = 146.20/x
  3. Step 3: Cross multiply
    420.19x = 630.15 × 146.20
  4. Step 4: Simplify right side
    420.19x = 92,127.93
  5. Step 5: Solve for x
    x = 92,127.93/420.19
  6. Step 6: Final answer
    x = 219.25

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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.