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Finding the Fourth Proportional to 858.36, 1,287.06 and 615

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Solution

The fourth proportional to 858.36, 1,287.06 and 615 is: 922.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.36 : 1,287.06 = 615 : x
  2. Step 2: Convert to fraction form
    858.36/1,287.06 = 615/x
  3. Step 3: Cross multiply
    858.36x = 1,287.06 × 615
  4. Step 4: Simplify right side
    858.36x = 791,541.90
  5. Step 5: Solve for x
    x = 791,541.90/858.36
  6. Step 6: Final answer
    x = 922.16

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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.