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Finding the Fourth Proportional to 856.15, 1,283.01 and 639.48

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Solution

The fourth proportional to 856.15, 1,283.01 and 639.48 is: 958.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.15 : 1,283.01 = 639.48 : x
  2. Step 2: Convert to fraction form
    856.15/1,283.01 = 639.48/x
  3. Step 3: Cross multiply
    856.15x = 1,283.01 × 639.48
  4. Step 4: Simplify right side
    856.15x = 820,452.82
  5. Step 5: Solve for x
    x = 820,452.82/856.15
  6. Step 6: Final answer
    x = 958.30

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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.