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Finding the Fourth Proportional to 856.60, 1,284 and 485.94

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Solution

The fourth proportional to 856.60, 1,284 and 485.94 is: 728.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.60 : 1,284 = 485.94 : x
  2. Step 2: Convert to fraction form
    856.60/1,284 = 485.94/x
  3. Step 3: Cross multiply
    856.60x = 1,284 × 485.94
  4. Step 4: Simplify right side
    856.60x = 623,946.96
  5. Step 5: Solve for x
    x = 623,946.96/856.60
  6. Step 6: Final answer
    x = 728.40

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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.