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Finding the Fourth Proportional to 279.99, 420.10 and 143.12

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Solution

The fourth proportional to 279.99, 420.10 and 143.12 is: 214.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.99 : 420.10 = 143.12 : x
  2. Step 2: Convert to fraction form
    279.99/420.10 = 143.12/x
  3. Step 3: Cross multiply
    279.99x = 420.10 × 143.12
  4. Step 4: Simplify right side
    279.99x = 60,125.40
  5. Step 5: Solve for x
    x = 60,125.40/279.99
  6. Step 6: Final answer
    x = 214.74

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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.