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Finding the Fourth Proportional to 656.69, 906.17 and 420.21

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Solution

The fourth proportional to 656.69, 906.17 and 420.21 is: 579.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.69 : 906.17 = 420.21 : x
  2. Step 2: Convert to fraction form
    656.69/906.17 = 420.21/x
  3. Step 3: Cross multiply
    656.69x = 906.17 × 420.21
  4. Step 4: Simplify right side
    656.69x = 380,779.59
  5. Step 5: Solve for x
    x = 380,779.59/656.69
  6. Step 6: Final answer
    x = 579.85

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1.5x scale

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.