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Finding the Fourth Proportional to 656.10, 905.14 and 390.51

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Solution

The fourth proportional to 656.10, 905.14 and 390.51 is: 538.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.10 : 905.14 = 390.51 : x
  2. Step 2: Convert to fraction form
    656.10/905.14 = 390.51/x
  3. Step 3: Cross multiply
    656.10x = 905.14 × 390.51
  4. Step 4: Simplify right side
    656.10x = 353,466.22
  5. Step 5: Solve for x
    x = 353,466.22/656.10
  6. Step 6: Final answer
    x = 538.74

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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.