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Finding the Fourth Proportional to 390.90, 589.70 and 371.67

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Solution

The fourth proportional to 390.90, 589.70 and 371.67 is: 560.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.90 : 589.70 = 371.67 : x
  2. Step 2: Convert to fraction form
    390.90/589.70 = 371.67/x
  3. Step 3: Cross multiply
    390.90x = 589.70 × 371.67
  4. Step 4: Simplify right side
    390.90x = 219,173.80
  5. Step 5: Solve for x
    x = 219,173.80/390.90
  6. Step 6: Final answer
    x = 560.69

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.