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Finding the Fourth Proportional to 390.40, 538.78 and 224.67

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Solution

The fourth proportional to 390.40, 538.78 and 224.67 is: 310.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.40 : 538.78 = 224.67 : x
  2. Step 2: Convert to fraction form
    390.40/538.78 = 224.67/x
  3. Step 3: Cross multiply
    390.40x = 538.78 × 224.67
  4. Step 4: Simplify right side
    390.40x = 121,047.70
  5. Step 5: Solve for x
    x = 121,047.70/390.40
  6. Step 6: Final answer
    x = 310.06

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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.