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Finding the Fourth Proportional to 620.45, 856.21 and 340.69

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Solution

The fourth proportional to 620.45, 856.21 and 340.69 is: 470.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.45 : 856.21 = 340.69 : x
  2. Step 2: Convert to fraction form
    620.45/856.21 = 340.69/x
  3. Step 3: Cross multiply
    620.45x = 856.21 × 340.69
  4. Step 4: Simplify right side
    620.45x = 291,702.18
  5. Step 5: Solve for x
    x = 291,702.18/620.45
  6. Step 6: Final answer
    x = 470.15

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Double scale
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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.