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Finding the Fourth Proportional to 656.02, 905 and 390.30

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Solution

The fourth proportional to 656.02, 905 and 390.30 is: 538.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.02 : 905 = 390.30 : x
  2. Step 2: Convert to fraction form
    656.02/905 = 390.30/x
  3. Step 3: Cross multiply
    656.02x = 905 × 390.30
  4. Step 4: Simplify right side
    656.02x = 353,221.50
  5. Step 5: Solve for x
    x = 353,221.50/656.02
  6. Step 6: Final answer
    x = 538.43

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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.