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Finding the Fourth Proportional to 390.40, 536.34 and 349.50

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Solution

The fourth proportional to 390.40, 536.34 and 349.50 is: 480.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.40 : 536.34 = 349.50 : x
  2. Step 2: Convert to fraction form
    390.40/536.34 = 349.50/x
  3. Step 3: Cross multiply
    390.40x = 536.34 × 349.50
  4. Step 4: Simplify right side
    390.40x = 187,450.83
  5. Step 5: Solve for x
    x = 187,450.83/390.40
  6. Step 6: Final answer
    x = 480.15

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.